Energetics PhD ANNUAL REPORT - polito.it PhD ANNUAL REPORT 2015 6 | P a g e D. GROSSO: “Multi...

Energetics PhD ANNUAL REPORT 2015

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ENERGETICS PhD PROGRAM

2015 ANNUAL REPORT

Editors: L. Savoldi and P. Asinari


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This document contains a series of one-page reports from the students enrolled in the Energetics

PhD program at Politecnico di Torino, Italy, including the highlights of their research activity in

2015. The previous editions of the Annual Report can be downloaded from

https://didattica.polito.it/pls/portal30/sviluppo.scudo_new.visual?p_id_cds=301&p_id_sez=103

The program is currently managed by a Board, which is composed of professors from Dipartimento

Energia as follows

Pietro Asinari

Marco Badami

Gianni Coppa

Vincenzo Corrado

Mario De Salve

Alessandro Ferrari

Pierluigi Leone

Federico Millo

Antonio Mittica

Marco Perino

Piero Ravetto

Massimo Rundo

Massimo Santarelli

Laura Savoldi

Ezio Spessa

Vittorio Verda

Roberto Zanino (coordinator)

For additional information please contact [email protected] (+39 011 090 4490)

https://didattica.polito.it/pls/portal30/sviluppo.scudo_new.visual?p_id_cds=301&p_id_sez=103

mailto:[email protected]


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OUR SPONSORS


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CONTENT

G. BOCCARDO: “TIVANO Project – Hybrid Propulsion Systems for General

Aviation”………………………………………………………………………………... Pag. 9

T. BUSO: "Nearly Zero Energy Multifunctional buildings - Energy and Economic

Evaluation"..................................................................................................................... Pag. 10

M. CARAMELLO: " Thermal-hydraulics of steam generators and of safety systems for

advanced nuclear reactors " ……………………………………......................................... Pag. 11

A. CARDELLINI: "Multi-scale modeling approach of nanoparticle suspension"………. Pag. 12

S. CARLI: " Simplified modeling of heat transfer problems at the interface between different subsystems of a superconducting tokamak "................................................. Pag. 13

D. CARON: "Multiphysics analysis of Generation IV reactors"..................................... Pag. 14

Y. CASCONE: "Optimization of building envelope components with responsive materials "..................................................................................................................... Pag. 15

S. COSENTINO: "Optimal design and operation of energy systems through reduced order modelling"........................................................................................................... Pag. 16

C. CUBITO: "Analysis of the impact of innovative powertrain technologies on CO2 and pollutant emissions under real world driving conditions"............................................... Pag. 17

C. DELMASTRO: “Advanced Input Modeling for energy planning”……………………... Pag. 18

D. DIRUTIGLIANO: “Performance modeling of low energy buildings”………………….. Pag. 19

D. DRAGO: "Design, development and testing of SOFC short-stacks with special heat pipes plates integrated with H2 sources"....................................................................... Pag. 20

S. FANTUCCI: “Advanced building envelope energy retrofit”……………………………. Pag. 21

M. FERRARA: “Simulation-based optimization of high-performing building in future energy scenarios”……………………………………………………………………………… Pag. 22

D. FERRERO: "Design, development and testing of SOEC-based power-to-gas systems for conversion and storage of RES into synthetic methane"........................... Pag. 23

A. FROIO: “Multi-scale thermal-hydraulic modeling for nuclear fusion reactors”………. Pag. 24

R. FUSO: "Development of Stop & Start Sailing strategy for real-world driving cycles"………………………………………………………………………………………….. Pag. 25

M. GANDIGLIO: "Design, optimization and implementation of novel SOFC multi-generation power plants fed by various bio-fuels"………………………………………… Pag. 26


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D. GROSSO: “Multi scale energy infrastructures modelling and interregional trade analysis”………………………………………………………………………………………… Pag. 27

E. GUELPA: "Modeling strategies toward multiple scenario and fast simulations; application for fire safety and energy engineering"....................................................... Pag. 28

A. HADADIAN: "Energy harvesting based on magnetoelastic materials"...................... Pag. 29

S. HOH: "Development of methods for the determination of reactivity from flux measurements".............................................................................................................. Pag. 30

D. IEMMOLO: "Model-based gas mixture detection in NG-NG/H2 powered engines"… Pag. 31

M. JARRE: "Analysis of thermal energy load patterns in district heating systems"…... Pag. 32

G. KAZAS: "Energy Supply and Demand Management through Energy Storage and Demand Side Management".......................................................................................... Pag. 33

H. KHESTINEJAD: "Active control of gaseous injection for CNG engines"................... Pag. 34

D. LAURENZANO: “Control-oriented models for high efficiency flex fuel SI engines for the 2020+ targets”……………………………………………………………………………… Pag. 35

A. MAHESHWARI: “Innovative and ageing resistant Li-ion batteries for high electric energy storage in a smart grid framework”…………………………………………………. Pag. 36

M. MIRZAEIAN: "Numerical Simulation of the Cycle-to-Cycle Variation and Knocking Phenomena in Spark Ignition Engines"......................................................................... Pag. 37

M. MONTEROSSI: “Energy saving through an innovative aircraft turbine thermal control” …………………………………………………………………………………………. Pag. 38

F. PAOLICELLI: "Model-based control approaches for injection and combustion processes in diesel engines”…………………………………………………………………. Pag. 39

B. PEIRETTI PARADISI: “Proton acceleration by laser-matter interaction for oncology radiotherapy”…………………………………………………………………………………… Pag. 40

A. PIANO: “Advanced air management systems for future automotive diesel engine generations”…………………………………………………………………………………….. Pag. 41

P. PIZZO: "Development of innovative diagnostic tools for fuel injection systems (FIS) and design of new measurement devices for hydraulic test benches"........................... Pag. 42

A. PIZZOLATO: “Topology optimization for energy problems”…………………………… Pag. 43

M. RAFIGH: "Diesel engine modeling for efficient calibration"....................................... Pag. 44

L. RIETTO: "Energy systems integration: from building scale to urban scale"............... Pag. 45

F. SABA: "Towards the development of a National Standard for Thermal Energy and its application to smart heat meter calibration"............................................................... Pag. 46

M. SAMAVATI: “Design and analysis of SOEC-based systems for synthetic liquid fuels production”……………………………………………………………………………….. Pag. 47


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G. SERALE: “Getting closer the mismatch between RES availability and exploitation”.. Pag. 48

R. TAURINO: "Energy-efficient innovative seal for aircraft engines"............................... Pag. 49

R. TESTONI: "Modelling of radionuclides transport phenomena in environmental matrices for Safety Assessment".................................................................................... Pag. 50

Y. TONG: "CO2 Reduction Technologies for ICEs"........................................................ Pag. 51

L. VENTOLA: "High-efficiency heat transfer devices by innovative manufacturing techniques”……………………………………………………………………………………... Pag. 52

L. VIGLIONE: "Analysis of injection, mixture formation and combustion processes for innovative CNG Engines”…….……………..................................................................... Pag. 53

J. XU: “Analysis of charge motion, injection and mixture formation in a high-

performance CNG DI engine”…………………………………………………………... Pag. 54

Y. YANG: “Modelling of fuel consumption and emission formation for design and calibration of ICEs in conventional and hybrid powertrains”…………..…………............. Pag. 55


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First name: Giulio LAST NAME: BOCCARDO

Topic: TIVANO Project – Hybrid Propulsion Systems for General Aviation

Course year: 1st Tutor(s): F. Millo, P. Nuccio

Academic context [1] Millo, F., Gianoglio Bernardi, M., and Delneri, D., "Computational Analysis of Internal and External EGR Strategies Combined with Miller Cycle Concept for a Two Stage Turbocharged Medium Speed Marine Diesel Engine," SAE Int. J. Engines 4(1):1319-1330, 2011, doi:10.4271/2011-01-1142 [2] Millo, F., Mallamo, F., Arnone, L., Bonanni, M. et al., "Analysis of Different Internal EGR Solutions for Small Diesel Engines," SAE Technical Paper 2007-01-0128, 2007, doi:10.4271/2007-01-0128 [3] Millo, F., Mallamo, F., and Mego, G., "The Potential of Dual Stage Turbocharging and Miller Cycle for HD Diesel Engines," SAE Technical Paper 2005-01-0221, 2005, doi:10.4271/2005-01-0221

External collaborations

Kohler Co. \ Engines

Alenia Aeronautica

Gamma Technologies Inc.

Highlights of the research activity Pollutant emissions reduction is going to be one of the main research topics for the next decades, and also the aviation field will be involved, even if nowadays an international regulation has not yet been put in place for general aviation. In this framework, the TIVANO project aims to develop a Diesel-Hybrid powertrain for aircraft applications which has the potential to be several steps forward in terms of fuel consumption and CO2 emissions with respect to conventional gasoline engines currently adopted in general aviation. The design and optimization of this propulsion system is going to be achieved with a strong support from numerical simulation, and the first goal is to develop an integrated Simulink model that includes all the submodels from the different research groups involved in the TIVANO project. In particular the DENERG research unit’s activities have been focused on the development of the diesel engine model, which has been carried out by means of an extensive experimental characterization of a new off-road diesel engine developed by Kohler, featuring a new high pressure common rail system and a two stage turbocharger, which is quite close to the requirements of the TIVANO project. At first, the two-stage turbocharging system has been simulated during the experiments by using an external compressed air supply to a conventional single stage turbocharger, as shown in the attached figure. In this first phase the boosting requirements were set, the most suitable injector type was selected and a preliminary steady state calibration was developed. Then in the second phase, which is currently ongoing, the engine has been equipped with a proper two stage turbocharging system and installed in the dynamic test bench where the steady state calibration has been refined and the engine performance is going to be evaluated under transient conditions. Since the features of the test engine are similar to the requirements of the TIVANO’s engine, the data gathered from this huge experimental campaign have been used to develop a 1D-CFD model by means of the commercial code GT-Power, which will be implemented in the global TIVANO Simulink model, to be run in a global optimization algorithm.

1

st e 2

nd phase: 2 stage turbocharging system

GT-Power 2 stage turbo engine model


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First name: Tiziana LAST NAME: BUSO

Topic: Nearly Zero Energy Multifunctional Buildings - Energy and Economic Evaluations

Course year: 2nd year Tutor(s): Stefano Paolo Corgnati

Academic context [1] T. Buso, S. P. Corgnati, J. Kurnitski, Defining the Reference Hotel – toward nearly Zero Energy Hotels design,

Climamed 2015 - 8th

Mediterranean Congress of Heating Ventilation and Air-Conditioning, 10-11 September, 2015,

Juan-les-pins, France (Proceedings not published yet).


Istanbul Technical University (prof. Yilmaz Zerrin)

REHVA Taskforce “nearly Zero Energy Buildings in Mediterranean Climate”

UE project neZEH – nearly Zero Energy Hotels

Highlights of the research activity The European Commission provides Member States with a standardized methodology to be followed for the definition

of nearly Zero Energy (nZEB) and cost-optimal (CO) level of energy performances of buildings. Indeed these target

levels should overlap by 2020. Nonetheless, for non-residential buildings, they are both still blurry figures at Countries’

level. The PhD research carried on in the current year took the EU methodology as the starting point for the investigation and

customized it for better representing the case of multifunctional buildings, with, during these first years, a specific focus

on hotel buildings. The first step toward CO and nZEB level of energy performances was to draft the Reference Hotel

(RH). Built on literature review about the energy performance of hotel buildings stock, a methodology for defining a

Reference Hotel suitable for the application of cost-optimal methodology was proposed based on the sub-categorization

and classification of the main building category (Figure 1). The methodology was applied for the definition of an Italian

existing Reference Hotel.

The Italian RH was the starting point for the subsequent steps to the definition of CO and nZEB levels. As prescribed

by EU directives and based on the most recent

Italian regulation on nZEBs, Energy efficiency

measures (EEMs) and packages of EEMs are

being implemented in a building dynamic

energy simulation software, and their impact on

energy consumption and global cost is under

evaluation. Beside the established EU

recommendations, the PhD research is currently

developing an experimental revised version on

the methodology. Indeed, academic literature

suggests a positive relation between

environmental and financial performance in

property investments: in addition to the energy

savings related to the building renovation, co-

benefits can be reaped. Such co-benefits of

energy retrofit are currently being assessed and

included in the calculations of the energy and

economic performances.

HANDOBOOK/MANUALS/

EXPERIENCE/CODES/ETC.

EXPERTS’ ASSUMPTIONS

BUILDING STOCK

STATISTICAL DATA

SUB-

CATEGORY

parameters

CLASSES

CLIMATIC

ZONE

BUILDING

AGE

HOTEL SIZE

HOTEL

CATEGORY

OPENING

PERIOD

HOTEL RB

SUB-

CATEGORY

(hosting

functions)

REAL

RB

THEORETICAL

RB

EXAMPLE

RB

FORM

ENVELOPE

SYSTEM

OPERATION

Extra

service

n

FORM

ENVELOPE

SYSTEM

OPERATION

Figure 1. Graphical summary of the methodology for the selection of a Reference

Hotel and for its detailed description, based on the definition of sub-categories and

classes.


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First name: MARCO LAST NAME: CARAMELLO

Topic: Thermal-hydraulics of steam generators and of safety systems for advanced nuclear reactors

Course year: 2nd Tutor(s) : De Salve Mario, Bertani Cristina, Panella Bruno

Academic context [1] M. Caramello, M. De Salve, C. Bertani, B. Panella, Thermal hydraulic comparison of helical coil and bayonet tube steam generators for small modular reactors, in: ICAPP 2015. [2] M. Caramello, M. Gregorini, M. De Salve, A. Alemberti, B. Panella, Thermal hydraulic analysis of Alfred Bayonet tube steam generator, in ICAPP2015. [3] M. Caramello, C. Bertani, M. De Salve, Helical coil thermal hydraulic model, J. phys.Conf. Series 547


Ansaldo Nucleare

SIET

POLIMI

Highlights of the research activity During my second PhD year I performed the following activities: - Characterization of ALFRED DHR-1 system: I studied the behavior of the safety system as a function of

its geometrical and physical parameters. The study permitted to deepen the knowledge of the safety system response for various designs. Sensitivity analyses covered the dimension of the gas tank and the isolation condenser headers, the mass

of water stored in the system, the initial pressure of the system and the type of noncondensable. - Thermal-hydraulic study of ALFRED steam generator: Starting from the frozen steam generator configuration I developed a sensitivity analysis on the conductivity of the insulating paint, on the length of the bayonets and on the diameter of the slave tube with the aim to characterize their effect on the pressure drops, the number of required bayonets, the average heat flux and the regenerative heat transfer. This study permitted to understand the impact of these parameters in case of design modifications. - Comparative study of compact steam generators in the light of Small Modular Reactors (SMR): in this study I developed a methodology for the comparison of compact steam generators and applied it for helical coil and bayonet heat exchangers to be used in the SMART reactor. The study permitted to compare the two configurations from the point of view of compactness, pressure drops and heat transfer. The behavior of the heat

exchangers was also studied under suitable hypotheses of low power loads.

- Improvements of the Matlab model for the characterization of helical coil steam generators: during the second year I updated the numerical model for the characterization of helical coil steam generators by adding the capability to study this component in fast reactors systems. The model is now equipped with sodium, lead and LBE properties, as well as suitable correlations to estimate the heat transfer and the friction pressure drops for this kind of liquids. A preliminary evaluation of the model performance involved the study of the helical coil steam generator of the BREST reactor. I acquired the skills needed to use the freeware softwares SALOME, OpenFoam and ParaView.

Number of bayonets for

ALFRED steam generator as a

function of the insulator thermal

conductivity


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First name: Annalisa LAST NAME: CARDELLINI

Topic: Multi-scale modeling approach of nanoparticle suspension

Course year: 2th Tutor(s): Pietro Asinari and Eliodoro Chiavazzo

Academic context [1] Moradi, A. et al, Journal of. Nanoscience and Nanotechnol., 2015. 15(5): 3488.

[2] Shih, Chih-Jen, et al., The Journal of Physical Chemistry C , 2015. 119(2):1047-1060

[3] Chiavazzo, E., et al, Scaling behaviour for the water transport in nanoconfined geometries. Nature communication., 2014. 5: 4565.


Burkhard Dunweg, Max Planck Institute for Polymer Research, Mainz, Germany

Highlights of the research activity

Suspending nanoparticles in traditional fluids can drastically enhance their optical properties and improve the

thermo-physical performances in both energy and biomedical applications [1]. The multiscale nature of such

nanofluids highlights the need of a model, which relates the nanoscale characteristics with the resulting

macroscopic properties. This multiscale model will allows to guide the rational design of nanosuspensions,

thus facilitating technology transfer from lab experiments to large scale industrial production.

The first steps of a suitable bottom-up Coarse Grained (CG) approach for nanofluids has been tailored and

employed. By means of Molecular Dynamics (MD) simulations, the pair Potential of Mean Forces (pPMF)

between a couple of alumina nanoparticles (NPs) solvated in water is evaluated. The procedure is applied to

several couples of 𝐴𝑙2𝑂3 NPs, with different surface charge

density and salt concentration of the solution.

The results shown in Fig. 1 depict the interaction potentials

when either charged (red dots) or neutral (blue diamonds)

nanoparticles are simulated. While approaching one each

other, the charged NPs experience a repulsive potential (Fig.

1, red dots), instead the neutral alumina particles cluster

(Fig. 1, blue dots). The fitting of the MD results is then

studied in light of the DLVO theory [2], which is current the

milestone to model interactions between colloidal particles

and their aggregation behavior. Besides the attractive term

and the repulsive electrostatic double-layer, well known from

the DLVO model, the inter particle potential here evaluated

shows an extra repulsive contribution. Such term has been

attributed to the hydration effects and to the enhanced water

density occurring at the solid-liquid interface [3]. Hence, the

hydration repulsive term has been added to the theoretical

potential in order to give a complete picture of the

interactions between suspended nanoparticle.

Finally, a systematic investigation of the pPMF on a wide

range of suspended nanoparticles, with different geometrical and chemical properties, will allow defining the

Coarse-Grained potential of nanofluids. This plays a crucial role in studying the complex mechanism of

nanoparticle clustering which is known to rule nanofluids stability as well as effective optical and thermal

properties.

rcom Distance

Figure 1: Molecular Dynamics results of the pair Potential of Mean Forces (pPMF) between the 𝛼 − 𝐴𝑙2𝑂3 NPs in salt solution (NaCl = 0.01 M) at different centre-of-mass distances.


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First name: Stefano LAST NAME: CARLI

Topic: Simplified modeling of heat transfer problems at the interface between different subsystems of a superconducting tokamak

Course year: 2nd Tutor(s): Laura SAVOLDI, Fabio SUBBA

Academic context [1] L. Savoldi Richard, F. Casella, B. Fiori, R. Zanino, “The 4C Code for the Cryogenic Circuit Conductor and Coil modeling in ITER”, Cryogenics, vol. 50, pp. 167-176, 2010. [2] S. Carli, R. Bonifetto, L. Savoldi Richard, and R. Zanino, "Incorporating Artificial Neural Networks in the dynamic thermal-hydraulic model of a controlled cryogenic circuit", Cryogenics, vol. 70, pp. 9-20, 2015. [3] S. Wiesen, D. Reiter, V. Kotov, M. Baelmans, W. Dekeyser, A.S. Kukushkin, S.W. Lisgo, R.A. Pitts, V. Rozhansky, G. Saibene, I. Veselova, S. Voskoboynikov, “The new SOLPS-ITER code package”, Journal of Nuclear Materials, vol. 463, pp. 480-484, 2015.


ITER, Cadarache (France).

EUROfusion

Highlights of the research activity In the last year, a new approach for the simplified modeling of the cooling loops of superconducting (SC) magnets for tokamak fusion reactors has been developed at PoliTo using Artificial Neural Networks (ANNs), where the dynamic response of the coil is hidden in an ANN black-box, while the 4C [1] model of the cooling circuit, on which control/regulation acts, is left untouched. The feasibility of the approach has been proven with respect to 4C results and experimental data from the HELIOS facility (CEA-Grenoble, France) [2].

Two ANN-based models have been developed for the ITER Central Solenoid (CS) and Toroidal Field (TF) magnets, able to cope with control/regulation of the cooling circuits. The models, trained using 4C simulations, have been tested against 4C results to prove their accuracy and then have been applied for a fast development of strategies to smooth the heat loads to the cryoplant coming from the magnets operation. Once the best strategy has been found, in terms of controlled variable and parameters of the controller, it has been implemented in 4C and the simulation results compared with those of the ANN models, checking their accuracy.

4C components have been developed in order to couple the ANN-based models with a simplified model of the Cryoplant, for a comprehensive model of the ITER magnet cooling system.

In the ITER tokamak fusion reactor, under construction in Cadarache (France), the power coming from the plasma is exhausted in the divertor, see Fig. 1. The vertical targets (VTs), where the strike points lie, have to sustain heat fluxes of 10 MWm

-2

at steady state and 20 MWm-2

in transients, while the reflector plates (RPs) fluxes of 5 MW

-2 at steady state and 10 MW

-2 for 2 s.

The heat flux profile has been obtained in the standard operation scenario of ITER, with baseline magnetic equilibrium e nominal strike point position. The strike points can however move from their nominal position due to change in the equilibrium:

Using the recently developed SOLPS-ITER code [3], the strike points have been displaced down on the VT and simulations are undergoing to check the heat loads on the RPs.

A simplified heat transfer model is being developed for the cooling circuit of the VTs and RPs to evaluate the surface temperature and operational limits of the plasma facing components.

Fig.1. Current ITER divertor design.


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First name: Dominic LAST NAME: CARON

Topic: Multiphysics analysis of Generation IV reactors

Course year: 2 Tutor(s): Sandra Dulla, Laura Savoldi

Academic context [1] Bonifetto, R., Dulla, S., Ravetto, P., Savoldi Richard, L., Zanino, R. A full-core coupled neutronic/thermal-hydraulic code for the modeling of lead-cooled nuclear fast reactors. Nuclear Engineering and Design, 261, 85-94 (2013). [2] Tobias, A. Decay heat. Progress in Nuclear Energy, 5, 1-93 (1980). [3] Fei, T., Mohamed A., Kim, T. Neutronics Benchmark Specifications for EBR-II Shutdown Heat Removal Test SHRT-45R - Revision 1. ANL-ARC-228 (rev. 1) (2013).


ENEA

IAEA

Highlights of the research activity Multiphysics analyses are important for the design and safety studies of innovative nuclear systems. Some of these systems, cooled by liquid-metal, are under investigation in research programmes of the European Union. The research activity in the year 2015 is oriented towards the continued development of the neutronics modelling capabilities of the FRENETIC (Fast REactor NEutronics/thermal-hydraulICs) code [1] and its application to advanced nuclear fission systems, with a special focus on liquid-metal cooled fast reactors in hexagonal geometry. In particular, the work accomplished concerns the implementation of decay heat modelling capabilities [2] and the preliminary validation of the integral code in the context of a coordinated research project of the International Atomic Energy Agency [3]. As regards the decay heat modelling capabilities, an appropriate physical model is identified and implemented in a manner which is consistent with the quasi-static method of temporal integration of the code, thereby allowing the decay heat phenomenon to be practically included in transient computations which require a treatment of the neutron flux on the full phase space. As to the code validation, the neutronics and the thermal-hydraulics aspects of the Experimental Breeder Reactor-II (EBR-II) are identified and described, beginning from the true geometry and the actual materials of the reactor, as well as the conditions of the experiment, and ending in the creation of the appropriate input files and libraries for the code. Initial computed results, as compared to the experimental measurements, are promising, as shown in the figure. However, it can also be inferred from the comparison that the inclusion in the model of the photon heat deposition, neglected so far, is required to achieve a better comparison with the experimental data (not shown). Ongoing work involves then the development and the implementation of additional models of relevant physical phenomena, such as photon heat deposition and core thermal expansion.

Comparison of computed and experimental results of the normalised power (left)

and coolant temperature (right) for the EBR-II SHRT-45R transient.


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First name: Ylenia LAST NAME: CASCONE

Topic: Optimization of building envelope components with responsive materials

Course year: 2nd Tutor(s): M. Perino, A. Capozzoli

Academic context [1] Stevanović S., 2013. Optimization of passive solar design strategies: A review. Renewable and Sustainable Energy Reviews 25, 177-196. [2] Al-Sanea S.A., Zedan M.F., 2011. Improving thermal performance of building walls by optimizing insulation layer distribution and thickness for same thermal mass. Applied Energy 88, 3113-3124. [3] El Mankibi M., Zhai Z., Al-Saadi S. N., Zoubir A., 2015. Numerical modeling of thermal behaviors of active multi-layer living wall. Energy and Buildings 106, 96-110.


University of Cambridge

Norwegian University of Science and Technology

Please keep this space as Please keep this space as is

Highlights of the research activity To analyse the thermal behaviour of high performance and responsive building envelope components, numerical and experimental investigations were carried out both on opaque and transparent components. However, the main focus dealt with the application of Phase Change Materials (PCM) in the opaque envelope. A literature review of the application of optimisation analyses to the building envelope with PCM was carried out. Standard dynamic thermal performance parameters cannot be applied to opaque envelope components integrating PCMs due to the strong dependency of their thermo-physical properties on temperature. Therefore, a novel thermal characterisation of these components was performed by means of “equivalent” parameters, considering the relationship between phase change temperature and boundary conditions for a given location. Then, to investigate the effect of the thermo-physical properties of PCMs on the characterisation of the building component, a parametric analysis was performed for a set of six wall configurations characterised by a different order of the layers (e.g. massive, insulation and PCM). Post-processing analyses, including the construction of classification and regression trees, were performed to identify the main decision variables and trends. Results highlighted that the melting temperature of the PCM appeared to be the most important variable influencing the dynamic performance of the opaque component. To analyse a wider range of configurations, an optimisation procedure was set up. The distribution of the layers and the thermal properties of the PCM (up to two materials with different range of melting temperature) were varied in order to minimise the equivalent periodic thermal transmittance, while minimising also the overall thickness of the wall and the amount of PCM. Results of this analysis highlighted that wall configurations with the insulation in the inner and outer layer were preferred, together with a high spread of the melting range of the “low-temperature” PCM and low thermal conductivity.

Fig. 2 - Characterisation of three wall configurations by means of “equivalent” periodic thermal transmittance and time lag, for a set of PCM properties.


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First name: Sara LAST NAME: COSENTINO

Topic: Optimal design and operation of energy systems through reduced order modelling

Course year: 2st Year Tutor(s): V. Verda, A. Sciacovelli

Academic context [1] Xu J., Wang R. Z., Li Y.,“ A review of available technologies for seasonal thermal energy storage”, Solar Energy 103 (2014), 610–638. [2] Bejan A., Tsatsaronis G., and Moran M. “Thermal Design and Optimization”. Wiley 1996, New York. [3] Chinesta F., Ammar A., Cueto E. “Recent Advances and New Challenges in the Use of the Proper Generalized Decomposition for Solving Multidimensional Models”. Arch Comput Methods Eng 2010; 17: 327–350.


Iren S.p.A.

J V V A –FIRE & RISK-

S.I.T.A.F. S.p.A

Highlights of the research activity Optimization of complex energy systems is mainly employed for the design stage, often through accurate and computationally expensive models. In contrast, optimal operation and control of these systems are usually based on simplified and inexpensive models. My research work is focused on the development and application of accurate model techniques to the optimal design and operation of complex energy systems, with the requirements of being sufficiently flexible and fast. Two types of systems have been considered with the goal of exploring different fields of application: ground heat exchangers and tunnel ventilation systems. In both applications, the model order reduction technique called proper orthogonal decomposition (POD) has been applied to the equations describing heat and mass transfer. The reduced models, obtained from the equations in non-dimensional form, do not depend on the geometry, source terms, boundary conditions and initial conditions. As first application, a ground thermal storage system (GTES) with vertical boreholes supplied by a district heating network has been considered. In this system, investment costs and performances are competing objective functions. A multi-objective optimization strategy has been applied to investigate the optimal design. Operation of the GTES during a long period has been analyzed using the reduced model. The Pareto Front is shown in Figure 1 in which each optimal solution defines the corresponding design in terms of pitch (P) and installation depth (L). Once the system is designed, the selection of the optimal operation allows an improvement in the storage efficiency and an economic profit for the cogeneration plant. The POD model has been implemented in an optimization algorithm of the GTES in order to discover the optimal times for storing and retrieving additional thermal energy during the operation. Thanks to the reduced model various scenarios can be explored taking into account the daily prediction of thermal and electrical energy consumptions as well as electricity market prices. As a second application, the reduced model of the mass transport has been implemented into a Fuzzy Logic strategy for the optimal control of the sanitary ventilation in a tunnel in different operating conditions. The reduced model will be used in an algorithm for emergency ventilation management, to predict fire position and fire size during the event.

Figure 3. POD based multi-objective optimization of borehole TES system


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First name: Claudio LAST NAME: CUBITO

Topic: Analysis of the impact of innovative powertrain technologies on CO2 and pollutant emissions under real world driving conditions

Course year:2nd Tutor(s): Federico Millo

Academic context [1] Ciuffo, B., Marotta, A., Tutuianu, M., Anagnostopoulos, K., Fontaras, G., Pavlovic, J., Serra, S., Tsiakmakis, S., and Zacharof, N., The development of the Word-Wide Harmonized test Procedure for Light Duty Vehicles (WLTP) and the pathway for its implementation in the EU legislation, Transportation Research Record: Journal of the Transportation Research Board, pp 110-118, 2015 [2] Fontanaras, G. and Dilara, P., The evolution of European passenger car characteristics 2000–2010 and its effects on real-world CO2 emissions and CO2 reduction policy, Energy Policy, Volume 49, October 2012, Pages 719–730 [3] Marotta, A., Pavlovic, J., Ciuffo, B., Serra, S. and Fontaras, G., Gaseous Emissions from Light-Duty Vehicles: Moving from NEDC to the New WLTP Test Procedure, Environmental Science & Technology, 2015


JRC (Joint Research Center) – European Commission, Ispra

Highlights of the research activity The World Forum for Harmonization of Vehicle Regulations of the United Nation Economic Commission for Europe (UN/ECE/WP29) has brought governments and automobile manufacturers together to work on a new harmonized test procedure to be adopted around the world, called WLTP (Worldwide Harmonized Light Duty Test Procedure), which should be enforced starting from 2017 for the determination of type-approval values of CO2 emissions from light-duty vehicles. The introduction of WLTP procedure will not affect the pollutants emissions levels prescribed by the legislation, but the CO2 targets will need to be adapted, since current values were set on the basis of NEDC test values. The measurements on WLTP will therefore need to be correlated to the equivalent NEDC using a correlation function or Meta-Model. Within this context, the research project, which is being carried out in close cooperation with the Joint Research Center (JRC) of the European Commission, is focused on the development of a Meta-Model to be applied both to Hybrid Electric Vehicles (HEVs) and Plug-In Hybrid Electric Vehicles (P-HEVs). The Meta-Model is based on a simplified physical approach, which, starting from the measurements along the new driving cycle, should be able to detect the behavior of the vehicle along the NEDC and to estimate with a good accuracy the CO2 emissions (within ± 3 g/km).The development of the Meta-Model has been carried out on a HEV C-segment vehicle equipped with a e-CVT architecture, evaluating the ICE ON/OFF strategy, the Smart Charge and Electric Boost depending on the battery State Of Charge (SOC).The predictive capabilities of the Meta-Model have been validated only for the “Hot Start” case and considering only one vehicle. In the next year the impact of “cold start” will be investigated and the model validation will be extended to other HEV and P-HEV vehicles.

Schematic representation of the Meta-Model

approach


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First name: Chiara LAST NAME: DELMASTRO

Topic: Advanced Input Modeling for energy planning

Course year: 1st year Tutor(s): S.P.Corgnati, A. Carpignano

Academic context [1] Lund, H., Zinck Thellufsen, J., Aggerholm, S., Wittchen, K.B., Nielsen, S., Mathiesenc, B.V., Möller, B., (2014), Heat savings strategies in sustainable smart energy systems, International Journal of Sustainable Energy Planning and Management (4), 3-16. [2] Mikkola, J., Lund, P. D., (2014), Models for generating place and time dependent urban energy demand, Applied energy (130), 256-264. [3] Di Leo, S., Pietrapertosa, F., Loperte, S., Salvia, M., Cosmi, C., (2015), Energy system modeling to support key strategic decisions in energy and climate change at regional scale, Renewables and sustainable energy reviews (42), 394-414.


IEA, International Energy Agency, SPT/ETP/EDT Division (Guest-PhD May-August and October-November)

IVL, Swedish Environmental Research Institute

Highlights of the research activity It is well known that urban areas represent a key opportunity for enhancing energy efficiency toward a low carbon community. Researchers and analysts can support local energy planning actions through exploring cost-effective, integrated technologies options for reaching the proposed long-term goals by using energy models. Since energy system models have mostly been used for large-scale analysis and are new to urban areas, many improvements can be made for enhance the reliability and the level of detail of the results. In this first year of the PhD, in partnership with the IEA and to be adopted in the forthcoming ETP 2016 publication, two preliminary models (one on residential buildings and one on district heating) have been developed to explore the effects of building energy efficiency measures on the district-heating network in Turin to 2050. Nine possible scenarios have been considered from a discounted life-cycle cost perspective –TLCC- (Figure) in order to understand, with respect to energy savings and CO2 emission reduction, which are the cost-effective patterns considering both investment on energy conservation and district heat supply options. With respect to business as usual scenario, energy savings in buildings would allow increasing the use of small scale heat production and of low grade heat (e.g. renewables, waste heat); moreover, the expansion of the network will be beneficial for lowering the cost of heat production and further reducing energy CO2 emissions. Results point out that energy savings in buildings without any intervention on district heating side will not reduce the TLCC from a system perspective; thus, they suggest that a strategic long-term vision that integrates building energy interventions and low carbon heat investments allows deep energy reductions and emission savings. This result support the relevance of the planned PhD’s future activities in which is expected to implement a integrated model by using the TIMES platform and to include the effects of energy price variations on the market and the competition among the different technologies. A special attention will be devoted to the behavioral theories related to the role socio-demographic variables in the penetration of retrofit measures.

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First name: Domenico LAST NAME: DIRUTIGLIANO

Topic: Performance modeling of low energy buildings

Course year: 1st Tutor(s): Vincenzo Corrado

Academic context [1] V. Corrado, I. Ballarini, D. Dirutigliano, S. Paduos, Cost-optimal analysis of Italian office buildings through the application of a quasi-steady state model validated by detailed dynamic simulation, IBPSA Building Simulation Conference 2015, proceeding in press, Hyderabad, India, 7-9 December 2015. [2] A. Buonomano, F. Calise, G. Ferruzzi, A. Palombo, Dynamic energy performance analysis: Case study for energy efficiency retrofits of hospital buildings, Energy 78, 2014, 555-572. [3] C. J. Hopfe, J.L.M. Hensen, Uncertainty analysis in building performance simulation for design support, Energy and Buildings 43 (2011) 2798–2805.


ENEA: Ricerca di Sistema elettrico Definizione degli edifici tipo di riferimento da utilizzare per i calcoli e le valutazioni di prestazione energetica degli edifici residenziali e non residenziali. Analisi delle prestazioni energetiche degli edifici, da applicare agli edifici di riferimento, per un confronto dei risultati tra calcolo stazionario e dinamico.

Highlights of the research activity The PhD research is focused on the implementation and validation of existing simplified energy performance assessment models and on the development and validation of new simplified models for the energy evaluation of advanced components of building construction and HVAC systems. The first part of the first year activity consisted in the analysis of the state of the art with regard to scientific literature, legislation and technical standards about nearly Zero Energy Building (nZEB), with particular focus on heating, cooling and ventilation systems. The design of a nZEBs includes the building envelope (opaque and transparent), the heating and cooling systems, the renewable sources and the energy management systems. The energy performance assessment can be carried out over an average period (e.g. monthly) or on hourly basis (or lower than hourly). The second stage of the research project was to compare these methods, namely the quasi-steady state method (monthly period) and dynamic method (1/4 hourly period) through simulation of office buildings. The simulation was run for three cities in Italy with two different building structures and two types of system management. The monthly and annual primary energy for heating and cooling were compared. The third stage in the first year was focused on the definition of the case studies of real buildings. The chosen case studies are a branch of the Università degli Studi del Piemonte Orientale Amedeo Avogadro in Alessandria and the Office building of the Province of Torino in Torino; both are non residential buildings, with heating and cooling systems and with mechanical ventilation. The first one has been recently constructed (year 2002), and the second one was refurbished in the 2008 year. These real cases will show the critical issues of nZEBs designing and they will help to direct the research activity towards the study of advanced solutions concerning building envelopes and/or technical systems.

Figure1 - Comparison of the primary energy indexes for heating and cooling systems between quasi-steady state model (UNI/TS 11300) and dynamic simulation (E+) for an office building in Rome.


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First name: Davide LAST NAME: Drago

Topic: Design and development of SOFC stacks with special heat pipes integrated with renewable H2 sources

Course year: 3rd Tutor(s): Massimo Santarelli

Academic context [1] P. V. Aravind, W. de Jong, “Evaluation of high temperature gas cleaning options for biomass gasification product gas for Solid Oxide Fuel Cells”, Progress in Energy and Combustion Science 38 (2012), 737 – 764. [2] S. Rasi, A. Veijanen, J. Rintala, “Trace compounds of biogas from different biogas production plants”, Energy 32 (2007), 1375 – 1380. [3] D. D. Papadias, S. Ahmed, R. Kumar, “Fuel quality issues with biogas energy – An economic analysis for a stationary fuel cell system”, Energy 44 (2012), 257 – 277.


--

Highlights of the research activity The work underwent to some changes basically due to the consequence of an update process of the system that is object of study. The changes occurred both in the layout of the system and in the field of application. Referring to the layout, the heat pipes filled with diphenyl ether (the cold ones) have been removed together with the metal hydrides tank. In the new arrangement, the surplus heat produced by the SOFC stack and extracted by the liquid sodium heat pipes will be directly involved in the processes of production and cleaning of biogas from waste organic products. These changes in the arrangement and in the choice of the fuel make it possible to use the system in wider contexts than the residential one. In particular, in this case the attention has been focused on a farm fed by biogas directly produced by waste products of the farm itself. The work can be divided into two main activities: the evaluation of the effect of different contaminants, potentially present in the biogas, on the normal operation of SOFCs and the study of the feasibility and efficiency of the new system considered.

Figures. At the left is shown a simple scheme summarizing the main modules that will compose the new system studied; at the right is shown the Nyquist diagram for a SOFC exposed to different concentrations of H2S. The first activity was carried out by adopting the Electrochemical Impedance Spectroscopy (EIS) method. This kind of analysis was conducted preliminarily with respect to the system analysis in order to verify the feasibility of using SOFC systems in contexts in which the available fuels could not be totally “clean”. Instead, the analysis of the complete plant foresees the use of the Aspen software. This analysis is still ongoing and will allow to determine the best possible configuration in terms of thermal balance and overall efficiency.

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First name: Stefano LAST NAME: Fantucci

Topic: Advanced building envelope energy retrofit

Course year: 1st Tutor(s): M. Perino, V. Serra

Academic context [1] A. Binz, A. Moosmann, et al., Vacuum insulation in the building sector: Systems

and application (Subtask B), IEA/ECBCS Annex 39 (2005). [2] M. Perino et al., State of the art review: Responsive building elements, IEA/ECBCS Annex 44 (2010). [3] S. Brunner, et al., Vacuum insulation panels for building applications, Energy and Buildings 85 (2014).


Prof. Giorgio Baldinelli - Università degli studi di Perugia;

Cosimo Marinosci – Università di Bologna;

IEA ECB Annex 65 – (EMPA, CSTB, Fraunhofer…)

Highlights of the research activity The energy retrofit of existing buildings is one of the key issues in EU countries. In particular Italy presents a large energy demand reduction potential, since more than 60% of building stock is over 40 years old, and most of them has an energy consumption for heating and cooling higher than 150 [kWh/m

2]. A deep renovation of the buildings is needed and,

among the various feasible solutions, the intervention on the building envelope represents one of the most cost effective solution, playing also an important role in achieving better comfort conditions for the users. Nevertheless, the identification of the right strategy to be adopted on existing building components represent a complex task, since compatibility (from the esthetical, physical and technological point of view) should be carefully evaluated. In this framework there are different unexplored or marginally explored solutions that could address the task under novel perspectives:

- the use of RBE (Responsive Building Elements); - the application of advanced layers (reflective coatings, phase

change layers, high diffusivity layers); - the use of super insulating materials such as VIPs (Vacuum

Insulation Panels) and ABP (Aerogel Based Products); During the first year three advanced solutions for the building energy retrofit were investigated. Through a long term monitoring activity carried out both in summer and winter conditions, the energy performance of an external ventilated curtain wall integrated with the HVAC systems was investigated under different ventilation strategies and different design features. Moreover the experimental results were used to validate a dynamic simulation model built in ESP-r environment. The effect of the application of IR reflective materials in opaque building envelope components was numerically and experimentally investigated. Two configurations were tested: applied in internal surfaces of ventilated façades, in order to improve the reduction of solar heat gains in summer conditions; used as low emissivity coating in the bricks cavity surfaces in order to improve the brick thermal resistance. The use of super insulating materials in buildings was investigated in the framework of IEA ECB Annex 65 activities. The most relevant investigations were carried out at different scales: at component scale, the thermal bridging effects and the influence of different joint materials were investigated through both numerical and experimental analyses; at system scale, the thermal behaviour of a VIP insulated building façade was assessed and the influence of thermal bridging effects on the building energy performance was evaluated.

Fig 1. RBE - Integration of ventilation

strategies in opaque wall components.


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First name: Maria LAST NAME: FERRARA

Topic: Simulation-based optimization of high-performing building in future energy scenarios

Course year: 1 Tutor(s): Enrico Fabrizio, Marco Filippi, Marco Perino

Academic context [1] M.Bayraktar, E.Fabrizio, M.Perino, The “extended building energy hub”: A new method for the simultaneous optimization of energy demand and energy supply in buildings, HVAC&R Research 18 (2012), 67-87 [2] S.P. Corgnati, E. Fabrizio, M. Filippi, V. Monetti, Reference buildings for cost optimal analysis: Method of definition and application, Applied Energy 102 (2013), 983-993 [3] M. Ferrara, E. Fabrizio, J. Virgone, M. Filippi, A simulation-based optimization method for cost-optimal analysis of nearly Zero Energy Buildings, Energy and Buildings 84 (2014) 442-457


IEA ECES Annex 31 – Energy storage with energy efficient buildings and districts: optimization and automation

CETHIL – Centre d’Energétique et de Thermique de Lyon

Highlights of the research activity The advancements in the research can be summarized in the following topics:

State of the art analysis Since the recast of the Energy Performance of buildings Directive (2010/31/EU) and the related introduction of the cost-optimal analysis (COA), many scientific studies were published about the application of the COA to the nZEB design. However there is still a lack of a shared vision on the most promising technologies and methodologies for bridging the gap between the zero energy goal and the economic affordability. A detailed literature review on these studies was performed in order to identify the current energy performance level associated to the cost optimal levels across Europe, the most promising technologies and the financial trends on which the future scenarios should be based.

Advancements in simulation methods Future buildings will be strictly related to renewable energy sources and therefore to multi-source multi-product energy systems. The methodology for modeling these complex systems in transient conditions was investigated. A first modeling application was done on a SAGHP (Solar assisted ground source heat pump) for a commercial building in extreme climate and a second application on an innovative system able to recover and store waste heat from the condenser of the chiller.

Advancements in optimization methods The optimization problem of the future building design was studied and formalized, identifying the objective function, the variables and the constraints of the problem. Different evolutionary algorithms were studied and some preliminary applications were done, one investigating the role of the energy system in the cost optimal design of nZEB and others concerning the multi-objective optimization of the building envelope design considering the total energy demand and the comfort.

Variation in the cost optimal design of building envelope according to the building

energy system (1-reversible heat pump, 2-electric radiators, 3-gas condensing

boiler, 4-wood boiler). On the x-axis: optimization parameters (Insulation thickness in walls, roof and slab, window type adn dimensions in different orientations). On

the y-axis: variation in energy performance with respect to the reference building

configuration due to variation of each optimization parameter.


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First name: Domenico LAST NAME: FERRERO

Topic: Design, development and testing of SOEC-based power-to-gas systems for conversion and storage of RES into synthetic methane

Course year: 3rd Tutor(s): Prof. Massimo Santarelli

Academic context [1] C. Graves et al., Sustainable hydrocarbon fuels by recycling CO2 and H2O with renewable or nuclear energy, Renewable and Sustainable Energy Reviews, Volume 15 (1), 2011, pp. 1–23. [2] H. Zhu et al., Modeling Elementary Heterogeneous Chemistry and Electrochemistry in Solid-Oxide Fuel Cells, Journal of The Electrochemical Society, Volume 152 (12), 2005, pp. A2427-A2440. [3] Q. Cai et al., Optimal control strategies for hydrogen production when coupling solid oxide electrolysers with intermittent renewable energies, Journal of Power Sources, 2014, Volume 268, pp. 212-224.


CNR ISTEC

Solidpower

Highlights of the research activity The research activity is focused on the analysis of Power-to-Gas (P2G) systems for RES electricity storage based on Solid Oxide Electrolysis Cells (SOEC). Different system configurations have been analyzed: reversible operation of Solid Oxide Cells for hydrogen production and reutilization and co-electrolysis of H2O and CO2 for syngas production and upgrading to Synthetic Natural Gas through methanation processes. System simulation for the identification of the operating conditions for an SOEC integrated in a P2G system has been performed. The operating conditions (e.g. inlet reactant stream composition, electric load) identified are used as input conditions of a solid oxide cell model developed at the level of Stack Repeating Unit (SRU). A thermo-electrochemical model of a single cell has been developed in the first year of research activity; the model was validated by performing experimental investigations (polarization and EIS measurements) on commercial cells tested in fuel cell and electrolysis modes. The model has been extended at the level of SRU during the second year of research by adding the description of fluid flows in the channels and a chemical model to take into account the catalytic reactions within the fuel electrode. The model has been applied to stationary and dynamic simulations to study the thermal response of the SRU in fuel cell and electrolysis operation. In the third year, the chemical model has been extended by taking into account also the carbon deposition reactions (Boudouard and methane cracking) and the effect of sulfur poisoning on the catalytic activity of the materials. Experiments have been performed on electrode materials to study the reaction kinetics and calibrate the models. The SRU model has been applied to simulate the relevant operating conditions of an SOC in a P2G system and to derive performance parameters to be used at system level in the simulation of the integrated P2G-SOC. System simulations are finally performed to study control strategies and for the optimization of process parameters.

Schematic of the research workflow


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First name: Antonio LAST NAME: FROIO

Topic: Multi-scale thermal-hydraulic modeling for nuclear fusion reactors

Course year: 1st Tutor(s): Laura SAVOLDI

Academic context [1] S. Hermsmeyer, U. Fischer, M. Fütterer, K. Schleisiek, I. Schmuck, H. Schnauder, “An improved

European helium cooled pebble bed blanket”, Fusion Engineering and Design, vol. 58-59, pp 689-693 [2] R. Zanino, R. Bonifetto, F. Cau, A. Portone and L. Savoldi Richard, “CFD Analysis of the ITER first wall

06 panel. Part I: Model set-up and flow distribution”, Fusion Engineering and Design, vol. 89, 2014, pp. 442-455.

[3] R. Zanino, R. Bonifetto, F. Cau, A. Portone and L. Savoldi Richard, “CFD Analysis of the ITER first wall 06 panel. Part II: Thermal-hydraulics”, Fusion Engineering and Design, vol. 89, 2014, pp. 431-441.


Karlsruhe Institute of Technology

EUROfusion

Highlights of the research activity The development of a global thermal-hydraulic model of the EU DEMO tokamak, launched by the EUROfusion PMU, is currently ongoing at Politecnico di Torino. The first module of this model will focus on the breeding blanket (BB) cooling system, and it should be developed in a modular fashion, to be able to investigate different cooling fluids and different cooling schemes, in order to be adapted to the different blanket systems under investigation in the BB project. In the first year, the system-level model for the Helium-Cooled Pebble Bed (HCPB) [1] is developed. The model is based on an object-oriented approach using the Modelica language. This system-level model comprises all the components of the cooling loops. The objects modelling the standard ex-vessel components, such as valves, pumps, compressors, heat exchangers and pipes, are taken from ThermoPower, a publicly available Modelica library, while the objects for the in-vessel components are developed ad-hoc, implementing the 1D time-dependent mass, momentum and energy conservation equations for the fluid flow; the thermal coupling between the twin countercurrent circuits is also accounted for. The ad-hoc in-vessel objects are all inside the segment model, which contains six Breeding Modules (BMs); each BM object contains, in turn, a number of First Wall (FW) channels and a Breeding Zone (BZ), made of several Cooling Plates (CPs). The information about friction factor and heat transfer in the FW channels are obtained from CFD and experimental analyses carried out at KIT; similar analyses shall be performed for other components, such as the manifolds, during the second year, exploiting the expertise of the group in CFD analysis [2-3]. The solid structures are lumped in a 1D object, i.e. they are modelled as the walls of the channels, and the transient energy balance is solved. The model is preliminarily applied to compare different values of heat loads to the system, and will be used to check the opportunity to adopt different cooling schemes, as, for instance, to compare the two cooling options for FW and BZ: Integrated (HCPB-I), where the FW and BZ are cooled in series, and Separated (HCPB-S), where FW and BZ are cooled by two independent circuits.

Fig. 1: Schematic of the HCPB cooling loops.

The twin circuits A and B are coupled at the BM

level (CV: Check Valve; HX: Heat eXchanger;

RC: Ring header Collector; RD: Ring header

Distributor; V: Volume; BM: Breeding Module; S:

Sector; I: Inlet; O: Outlet).


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First name: Rocco LAST NAME: Fuso

Topic: Development of Stop & Start Sailing strategy for real-world driving cycles

Course year: 3rd Tutor(s): Federico Millo, Ing. M.Cisternino

Academic context [1] Mueller, N., Strauss, S., Tumback, S., Goh, G. et al., "Next Generation Engine Start/Stop Systems: “Free-Wheeling”," SAE Int. J. Engines 4(1):874-887, 2011, doi:10.4271/2011-01-0712. [2] Dunn, A., Uhlenhake, G., Guenther, D., Heydinger, G. et al., "Vehicle Coast Analysis: Typical SUV Characteristics," SAE Int. J. Passeng. Cars - Mech. Syst. 1(1):526-535, 2009, doi:10.4271/2008-01-0598. [3] Kopin, A. and Musselman, S., "Complete Vehicle Standards for Heavy-Duty Trucking: Optimizing Freight Efficiency Benefits to Meet U.S. Greenhouse Gas Emission Standards," SAE Int. J. Commer. Veh. 8(2):400-

418, 2015, doi:10.4271/2015-01-2772.


General Motors-Powertrain Europe

Highlights of the research activity The “sailing” feature allows the best exploitation of the kinetic energy of the car [1], providing a new driving experience efficient and environmentally friendly. By enabling such a feature the clutch is automatically disengaged, so the car can move forward by inertia, decreasing fuel consumption due to the engine switch-off. The advantage in terms of fuel consumption comes from the use of the kinetic energy of the car in order to overcome the rolling and aerodynamic resistances [2-3]. If the driver request, made through the accelerator or brake pedal, results to be different from the ‘natural’ vehicle deceleration, the clutch is engaged immediately to take advantage of engine contribution. The efficiency of this feature depends on the driving style. During these three years, an innovative system controller has been developed with the aim of extend as much as possible the sailing advantages on a generic driving pattern representative of real-world operations. In order to prevent the lack of perceived safety by the driver, this new controller monitors time by time key aspects of the driver action, so as to rapidly detect any change of mind of the driver actuating the exit procedure and quitting the sailing maneuver. After a first series of numerical assessments of the control logic, the project moved to the testing facilities where the sailing potential was verified using a prototype on the roller test bench first, and on the streets after. The experimental tests proved that the sailing feature does not deteriorate diesel engine emissions. Furthermore, fuel savings of about 3% on WLTC cycle and 7% for real life applications were obtained. Special focus of the activity carried out during this last year was the evaluation of the sailing impact on the

drivability. A customer survey has been arranged on a GM test track to determine customers’ feedbacks

concerning “Tip In Delay” and “Bump After Vehicle Coasting”. The data collected during the test campaign

highlighted the need of improvements regarding the time elapsed to give back control to the driver when

maneuver ends.

Proto vehicle on the test-track during the survey


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First name: Marta LAST NAME: GANDIGLIO

Topic: Design, optimization and implementation of novel SOFC multi-generation power plants fed by various bio-fuels

Course year: 2nd Tutor(s): Prof. Massimo Santarelli

Academic context [1] A.A. Trendewicz, R.J. Braun, “Techno-economic analysis of solid oxide fuel cell-based combined heat and power systems for biogas utilization at wastewater treatment facilities”, 2013, Journal of Power Sources 233, 380-393. [2] P. Margalef, T. Brown, J. Brouwer, S. Samuelsen, “Conceptual design and configuration performance analyses of polygenerating high temperature fuel cells”, 2011, International Journal of Hydrogen Energy 36, 10044-10056.


Jack Brouwer - Advanced Power and Energy Program (APEP) at the University of California, Irvine.

SMAT – Società Metropolitana Acque Torino.

Convion Oy – Solid Oxide Fuel Cell Produced, Helsinki (FI)

Highlights of the research activity The second year of my PhD has been devoted to two main activities:

Experimental activities on the SOFCOM (www.sofcom.eu) demo plant from Nov 2015 to May 2016.

Techno-economic analysis of a scaled-up version of the biogas fed SOFC system, with design of the new DEMOSOFC (www.demosofc.eu) concept.

Starting from the design activities of the first year, the SOFCOM plant has been installed and operated in the SMAT Waste Water Treatment Plant (WWTP) in Castiglione (TO). The plant was the first worldwide plant coupling a biogas fed 2 kWe Solid Oxide Fuel Cell (SOFC) with Carbon Capture and Use (CCU) in a photobioreactor for algae growth. The experimental activities were first devoted to the performance testing of each single unit, then to the long run (more than 600 hours) of the complete system. Results show that the system was able to run for hundreds of hours, carbon was captured and algae were growing thanks to the CO2 injection. Major problems were only related to the outdoor installation in the winter time.

Thanks to the positive experience of the SOFCOM project, a techno-economic analysis has been developed to understand the feasibility of a second project based on a real industrial installation of a SOFC system in a SMAT WWTP. After many technical and economic analyses, the proposal has been written and DEMOSOFC, a new European project, has been financed by FCH-JU: it is related to the installation of a 174 kWe biogas fed SOFC system in the WWTP of Collegno (TO). Now, the objective of my PhD is thus to move from the lab-scale design and results to an industrial and large scale design with related new challenges. Techno-economic analyses will be now devoted to the real operation of the system, analyzing the biogas fluctuations within the plant, the management of the heat recovery, the energy costs and the resulting control system of the overall plant. This activity is started during 2015 and will continue during next years. All these analyses have been developed in cooperation with the main DEMOSOFC partners, SMAT and Convion Oy, the Finnish SOFC producer. In Autumn 2016 the system will be installed and thus experimental results will available to validate the models and gain more experience on this new biogas plant concept.

Figure 1. Operation on the long run of the SOFCOM

demonstration plant.

http://www.sofcom.eu/

http://www.demosofc.eu/


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First name: Daniele LAST NAME: GROSSO

Topic: Multi scale energy infrastructures modelling and interregional trade analysis

Course year: 1st Tutors: A. Carpignano, M. Badami

Academic context [1] Martchamadol, J., Kumar, S. (2013): “An aggregated energy security performance indicator”, Applied Energy, Vol. 103, pp. 653-670. [2] Badea, A. C., Rocco S., C. M., Tarantola, S., Bolado, R. (2011): “Composite indicators for security of energy supply using ordered weighted averaging”, Reliability Engineering and System Safety, Vol. 96, pp. 651-662. [3] Rimkevicius, S., Kaliatka, A., Valincius, M., Dundulis, G., Janulionis, R., Grybenas, A., Zutautaite, I. (2012): “Development of approach for reliability assessment of pipeline network systems”, Applied Energy, Vol. 94, pp.22-33.


Sistema di informazione per la sicurezza della Repubblica

Highlights of the research activity The security of supply is one of the three main pillars of the EU energy policy (together with competitiveness and sustainability), and it can be related to several aspects, both geopolitical and technical. For this reason, new integrated approaches applied to the modelling and analysis of energy infrastructures (mainly oil & gas pipelines, but also internal and local distribution networks) are needed in order to keep together as much as possible all these dimensions and to define comprehensive analytic techniques for the measurement of the security level and the identification of critical sections and nodes. Tools able to perform these evaluations can thus be supporting systems for strategical choices. The first step of the research activity was focused on the definition of a methodology to quantify the risk related to the supply of the main commodities to Italy via energy corridors from a geopolitical point of view. For this purpose, a probabilistic approach was adopted, defining, for each corridor, a composite risk indicator (corresponding to the probability of failure in the supply from that corridor) as a function of the single risk indexes of the crossed countries, weighted – by means of a proper parameter – on the length of the corridor branches. The product between this indicator and the annual quantity of commodity flowing through the infrastructure in normal operational conditions (expressed in energy unit) gives the contribution of that corridor to the overall National external risk. The risk is thus evaluated, in accordance with the common definition of the risk analysis, as the product between a probability (the risk indicator) and a damage (the energy losses due to the failure of the corridor for geopolitical reasons); by introducing the Energy Intensity of the Economy parameter (defined as the ratio between the gross inland consumption and the gross domestic product), the risk value is converted from energy unit to monetary unit. A preliminary test on natural gas pipelines and a sensitivity analysis were performed. During next steps, a risk indicator related to the resilience of internal distribution networks and a procedure for the quantification of the National internal risk will be defined, together with the implementation of a georeferred tool.

Figure 4: Scheme for the definition of a National Energy Security index


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First name: Elisa ……LAST NAME: GUELPA

Topic: Modeling strategies toward multiple scenario and fast simulations; application to fire safety and energy engineering

Course year: 3rd Tutor(s): V. Verda, R. Borchiellini, A. Sciacovelli

Academic context [1] Sullivan, Andrew L. "Wildland surface fire spread modelling, 1990–2007. 1: Physical and quasi-physical models." International Journal of Wildland Fire18.4 (2009): 349-368. [2] Stevanovic, Vladimir D., et al. "Prediction of thermal transients in district heating systems." Energy Conversion and Management 50.9 (2009): 2167-2173. [3] Schilders, Wil. "Introduction to model order reduction." Model order reduction: Theory, research aspects and applications. Springer Berlin Heidelberg, 2008. 3-32.


Università degli Studi di Torino

Iren Energia

Università di Roma La Sapienza

Highlights of the research activity My research activity is focused on the development of model approaches for fast simulation of systems involving large domains and long timeframes. This type of problem is common to various engineering fields, where the analysis of multiple transient scenarios is requested. Two applications are considered in the present research: wildfire and district heating network (DHN). A two-dimensional physical model for wildfire evolution forecast has been obtained. The Proper Orthogonal Decomposition (POD) reduction has been applied to the 1D model considering the eigenfunctions travelling with the fire front. A simulation approach has been then adopted in order to obtain the 2D propagation. Comparisons with experimental measurements show that the basis obtained in a particular condition can be used to simulate propagation in different conditions (e.g. wind speed or fuel characteristics) with high accuracy and low computational costs. Two different uses of fast simulations of District Heating Networks have been successfully examined: optimal pumping and prediction of thermal load. POD has been first applied to obtain the optimal control strategy of the pumping groups of the Turin DHN, depending on the thermal request of the users and also considering possible unpredictable malfunctions. Such optimal strategy can lead to an average reduction of about 20% in the electricity consumption with respect to current strategy and better management of malfunctioning scenarios. A detailed thermal-fluid dynamic model for the simulation of temperatures and mass flow rates in large DHNs has been built and then applied to the analysis of transient operations of the Turin DHN. A comparison between simulation results and measured data shows that the model is able to predict the thermal load request to each plant with good accuracy. The POD technique has been then used to reduce the fluid dynamic problem and thus make simulations much faster. The approach allows optimization of the thermal request profiles of users and optimal integration of centralized and distributed thermal storage systems.

Figure 1 Results of POD modeling of

DHN and comparison with monitored

data.


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First name: Arash LAST NAME: HADADIAN

Topic: Energy harvesting based on magnetoelastic materials

Course year: XXVIII (28th CYCLE) Tutor(s): Prof. Mario Chiampi and Dr. Mauro Zucca

Academic context [1] Zucca, M. Bottauscio, O., Beatrice C., and Fiorillo, F,. “Modeling Amorphous Ribbons in Energy Harvesting Applications” IEEE Transactions On Magnetics, VOL. 47, NO. 10, Oct. 2011 [2] H. Chiriac, M. Tibu, N. Lupu, I. Skorvanek, and T.-A. Ovari, “Nanocrystalline ribbons for energy harvesting applications,” Journal of Applied Physics, vol. 115, pp. 17A320 (3 pp), 2014.


INRIM, Istituto Nazionale di Ricerca Metrologica, Metrology for the Quality of Life (MQL) Division.


The subject of the thesis is the analysis of different kinds of harvesters, which utilize the environmental

vibration to generate electrical power. During the first two years of my PhD direct force harvesters were

designed and analyzed experimentally and theoretically by simulation through a magneto-mechanical FEM

code. The first one was based on bulk material (Terfenol-D), which is suitable for high energy vibrations and

able to produce output power in the range of some tens of milliwatt. A second setup was tuned and analyzed,

based on amorphous material, which is suitable for low energy vibrations, and produced power of the order

of 10-2

mW.

During the third year, a cantilever structure has been designed and developed. Cantilevers have a single

constraint and are more suitable for miniaturization. The importance of the magnetic bias pattern has

been deepened in our investigation. In the considered prototype, the cores were made of either non-

oriented Fe-(3 wt%)Si and Fe50Co50 (Vacoflux 50) strips, annealed after cutting. The experiments show that,

besides the specific properties of the two soft magnetic alloys, a special role is played by strength and

direction of the magnetic field bias. This is generated

by small Nd-Fe-B magnets (from two to six) suitably

arranged in proximity of the vibrating soft magnetic

core. Three different magnet configurations, all

leading to significant electrical output power, have

been investigated in detail. The pattern of the dc

magnetic induction along the sample was

investigated both experimentally and through a finite

element model. The simulations were performed by

the 3D Opera FEM code. The local magnetization

was measured through 5 turn pickup coils placed in

three sections of the sample. A suitable beam length

was previously calculated by theoretical formulation

for resonance frequencies in the range 45 Hz - 65 Hz,

which corresponds to the vibration frequencies

available in many environments, especially industrial.

The maximum figures of the output power were

obtained in configuration #C (Fig. 1), in particular, 5.2 mW and 2.2 mW for the Fe-Co and Fe-Si cores,

respectively. The significant importance of the magnetic bias pattern has been pointed out.

Fig. 1 a) Three investigated configurations of

the Nd-Fe-B magnets, b) Schematic of

harvester structure, c) Harvester and soft

magnetic core. The induction along the core

free part is measured using three localized

pick up coils


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First name: Siew Sin LAST NAME: HOH

Topic: Development of methods for the determination of reactivity from flux measurements

Course year: 2 Tutor(s): Sandra Dulla, Piero Ravetto

Academic context [1] S. DULLA, S. S. HOH, M. NERVO and P. RAVETTO, “Importance weighting of local flux measurements to improve reactivity predictions in nuclear systems, KERNTECHNIK, 80, 201 – 207 (2015). [2] S. DULLA, M. NERVO, and P. RAVETTO, “Importance method for reactivity monitoring in subcritical source-driven systems, Proceedings of the International Conference PHYSOR 2014, Kyoto, Japan (2014). [3] D. CARON, S. DULLA, M. NERVO, P. RAVETTO, and M. CARTA, “Assessment of an on-line reactivity monitoring technique, Transactions of the American Nuclear Society, 111, 1185-1187, Anaheim, California

(2014).


IAEA

KUCA

Highlights of the research activity Reactivity monitoring is essential for accelerator driven systems (ADS), in which the system is operated in subcritical mode and maintains a steady state with the neutron injections by an external source. Hence a method for online reactivity monitoring is needed to detect potentially dangerous situations and to avoid a criticality accident. Point kinetic is usually employed for reactivity reconstruction from flux measurement owing to the simplicity of the model. Methods for the reduction of spatial and spectral effect are needed to improve the reactivity prediction. The MAρTA algorithm (Monitoring Algorithm for Reactivity Analysis) is a point kinetic-based algorithm that has been developed to reconstruct reactivity from flux measurements. Rather than applying correction factors, an alternative method of importance weighting on local flux signals is applied in this research. This method perform a linear combination of localized detector signals at different positions using the corresponding neutron importance as a weighting function to form a global signal before apply for reactivity reconstruction algorithm. This method is first applied in a test case where one-dimensional slab geometry for typical fast lead cooled system is considered. Neutron fluxes and adjoints are simulated at four positions using a deterministic code solving

the multigroup diffusion equations. The use of the technique shows a good improvement, even at the beginning of the transient, as compared to a single detector. This method is then applied to real experimental data obtained at the KUCA (Kyoto University Critical Assembly) accelerator-driven system. Full three-dimensional geometry is simulated with Serpent 2, a continuous energy Monte Carlo code, to obtain few group cross-sections to be used in ERANOS, a deterministic transport code, to compute the adjoint flux. To understand how the method can handle large space effects for large heterogeneous systems, MCNPX is

used to simulate a test highly heterogeneous configuration providing local flux and adjoint for various

positions in the system for a pulsed experiment. Also in this case the use of the technique leads to a significant improvement of the predictive capabilities of the technique.

Reactivity reconstruction by MAρTA


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First name: Daniele LAST NAME: IEMMOLO

Topic: Model-based gas mixture detection in NG-NG/H2 powered engines

Course year: 2ND Tutor(s): E. Spessa, D. Misul

Academic context [1] Baratta M., d’Ambrosio S., Iemmolo D., Misul D., “Influence of Different Compositions of Natural Gas on Engine Performance”, ASME ATI UIT 2015 proceedings, ISBN: 978-88-98273-17-1 [2] Baratta M., D'Ambrosio S., Misul D., Spessa E. (2014) “Effects of H2 addition to compressed natural gas blends on cycle-to-cycle and cylinder-to-cylinder combustion variation in a spark-ignition engine, Journal of Engineering for Gas Turbines and Power, vol. 136, 051502-1-051502-12. - ISSN 0742-4795 [3] Verhelst S., Wallner T., "Hydrogen-Fueled Internal Combustion Engines". Progress in Energy and Combustion Science, Vol. 35, pp. 490-527, 2009.


BioMethAir Project (Centro Ricerche Fiat)

Highlights of the research activity The need to reduce fuel consumption and exhaust emission in internal combustion engines has led the transportation sector to consider the use of alternative fuels such as natural gas (NG) and hydrogen enriched methane (HCNG). The production of HCNG from biomass results in a wide range of possible gas mixtures, having a strong impact of engine performance and emissions. The research work conducted this year focused on finding an algorithm capable of identifying which mixture is actually injected into the engine starting from data readily available from the engine control unit. The scenario in which the car is fueled at the gas station with an unknown mixture composition has been replicated on test bench by using different fuels, namely CNG, G25 (i.e. a mixture of 86%vol CH4 and 14%vol N2) and different blends of HCNG (from 10%vol to 30%vol of H2). Data acquired were used to build and validate the model. The fundamental problem is that the same injection duration will result in different injected mass depending on the gas mixture. From the theory of nozzles it is possible to evaluate a “normalized” mean injected mass that does not depend on the nature of the gas but just on geometrical factors and the injection duration. Experimental data were used to build a regression model which relies on the aforementioned fact and hence it can be applied for every gas mixture to be evaluated. Given a possible set of mixtures, the algorithm computes the relevant thermo-physical properties and using engine control unit data, like air-mass flow at the intake, estimates an injection duration. A subset of the starting mixtures which minimizes the error between the estimated and actual injection duration is then identified. Furthermore, since different mixtures can show very similar injection durations (i.e. similar injected mass), the stoichiometric air-to-fuel ratio is evaluated with a similar procedure and compared with the theoretical value of the given mixture. The mixture which shows the minimum error in term of injection duration and stoichiometric air to fuel ratio is than identified as the actual one (Figure 1).

Figure 2 – Stoichiometric air-to-fuel ratio error vs Injection duration error calculated for the recognition of G25.


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First name: Matteo LAST NAME: JARRE

Topic: Analysis of thermal energy load patterns in district heating systems

Course year: 29° cycle Tutor(s): Marco Masoero, Alberto Poggio

Academic context [1] E. Dotzauer - “Simple model for prediction of loads in district-heating systems”, Applied Energy 73 (2002) 277–284 [2] H. Gadd, S. Werner - “Heat load patterns in district heating substations”, Applied Energy 108 (2013) 176–183 [3] R. Drusiani - “Brevi note sulle modalità di calcolo della inerzia termica in un parco edilizio riscaldato a gas naturale”, relazione n. 306, AMGA Bologna (1983)


Highlights of the research activity During the second year of research, real thermal energy consumption data were collected, elaborated and analyzed in order to refine the carried simulations. Data acquisition was carried out by collaborating, mainly, with district heating companies that provided large quantities of very detailed data about the network substations. In addition to that, data acquisition was also carried out punctually, i.e. for specific buildings or groups of buildings. The final users’ thermal energy consumption modeling was carried out in two distinct phases:

As a first step, monthly/weekly or daily thermal energy consumption data were analyzed; their variability was studied as mainly a function of external temperature when monthly or weekly data are considered, whereas systems’ thermal capacity had to be considered when daily data are studied. This first step allowed determining a “global thermal resistance” value for each studied building. A specific instrument was developed from [3] in order to include thermal capacity within the thermal energy signature of the studied system; this instrument proved its capability of providing a good estimate of the building thermal capacity effect on its effective thermal energy consumption.

Once the first phase was concluded, a second-level analysis has been started by using hourly or sub-hourly thermal energy consumption data. This analysis, which is to be completed during the third year of research, aims at developing a simplified instrument to recreate the thermal energy consumption hourly profile of each available building. This will happen through (1) the development of a procedure to identify the different operation mode of the substation regulation system (peaks, steady-state phases, shut-downs and start-ups), (2) the calculation of different values of a number of thermal capacities characterizing the building thermal behavior, (3) the application of the built model to a large number of “virtual case-studies” to validate the model’s capability of predicting thermal energy consumption profiles with few input data.

Hourly Thermal Specific Power Profile for mean monthly

day for 4 months (October, December, February, March):

REAL (solid line) vs. MODEL (dots) for one example

building.


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First name: Georgios LAST NAME: KAZAS

Topic: Energy Supply and Demand Management through Energy Storage and Demand Side Management

Course year: 2nd Tutor(s): Prof. Marco Perino

Academic context [1] Swan, L.G. & Ugursal, V.I., 2009. Modeling of end-use energy consumption in the residential sector: A review of modeling techniques. Renewable and Sustainable Energy Reviews, 13(8), pp.1819–1835 [2] Kavgic, M. et al., 2010. A review of bottom-up building stock models for energy consumption in the residential sector. Building and Environment, 45(7), pp.1683–169 [3] Arteconi A. et al., 2012. State of the art of thermal storage for demand-side management. Applied Energy, 93, pp.371-389


CINERGY Marie Curie FP7-PEOPLE-2013-ITN

NUID University College of Dublin (Co-supervisor Dr. D. Finn)

SIEMENS

Highlights of the research activity The current PhD thesis investigates strategies for buildings’ energy demand optimization at urban district scale applying demand side management (DSM) techniques and thermal energy storage technologies (TES). In order to investigate the DSM and the use of TES, thermal energy demand profiles with detailed time resolution at district scale are needed. The project’s Activity I, which was carried out during the first 18-months, included the generation of an average thermal energy demand profile with hourly time resolution at urban district scale and the definition of typical monthly days. A bottom-up model was developed. Reference buildings (RBs) were identified and modelled, based on the samples of representative buildings technique. In order to cover the diversity of the building stock at district scale, a parametric analysis was applied. The parametric analysis took into account critical parameters of the buildings’ energy performance, like the occupants’ behavior. Parametric analysis resulted into a database of thermal energy demand profiles with hourly time resolution, normalized by the RB conditioned area. Using the database as a set of predicted district thermal energy demand profiles, profiles for a particular district extracted and after a statistical approach a common average profile of a block of buildings with an hourly time step was generated. To test and validate the current methodology, the model was applied in a block of buildings in Turin, Italy. A second case study that includes a district in Geneva, Switzerland is currently being studied. Activity II, which covers the future work, includes the application and integration of DSM techniques. DSM that was initially developed to match energy supply and demand includes various tools like TES. While DSM through TES was studied mainly at building scale or in centralized networks, the current project aims at developing a strategy for decentralized active TES integration at district scale to provide an integrated and efficient tool for district DSM. As part of the CINERGY project, that tool is going to be integrated into a platform for city-scale energy management, including other simplified and stochastic models of electrical loads, passive TES, thermal networks, optimization algorithms and 3D-GIS maps.

Figure: District thermal energy demand profiles selection


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First name: Hamed. LAST NAME: KHESHTINEJAD

Topic: ACTIVE CONTROL OF GASEOUS INJECTION FOR CNG ENGINES……..............

Course year: 2nd ....... Tutor(s): Daniela Misul – Mirko Baratta....

Academic context [1] Jan Czerwinski, Pierre Comte and Yan Zimmerli; “Investigations of the Gas Injection System on a HD-

CNG-Engine”, 2003 SAE World Congress Detroit, Michigan; Code: 2003-01-0625. [2] Alberto Boretti, Petros Lappas, Bingjie Zhang, and Siti Khalijah Mazlan; “CNG Fueling Strategies for Commercial Vehicles Engines-A Literature Review”, Journal of SAE International, 2013-01-2812, ISSN 0148-7191 [3] Mirko Baratta, Hamed Kheshtinejad, Danilo Laurenzano , Daniela Misul, Stefano Brunetti; “Modelling aspects of a CNG injection system to predict its behavior under steady state conditions and throughout driving cycle simulations”; Journal of Natural Gas Science and Engineering, 24 (2015) 52-63.


BioMethAir Project (Centro Ricerche Fiat, Metatron)

Consultant contract between Dip. Energia and Metatronix S.R.L; with the title “Simulazioni fluidodinamiche di sistemi di iniezione di gas naturale”

Highlights of the research activity The research activity includes the numerical investigation into the fluid dynamic behavior of a commercial CNG injection system by means of 0D-1D code. The experimental set-up has been carried out at Centro Ricerche Fiat (CRF) and Metatronix laboratories. The first stage of the study was focused on developing a thorough model of pressure regulator valve for CNG injection system. A detailed model of the pressure regulator has hence been developed and the model has been calibrated, tested and run under various operating conditions so as to assess for the experimental validation. The proposed valve model has proved to consistently reproduce the injection system response for different speed and load conditions. For the predictive mode, the fast transient operations have been considered to assess the response of the system to fast transient operations, both in terms of speed and load. The mismatch between the actually injected mass and the ECU target mass has proved the need for dedicated and refined control strategies to prevent anomalies in the mixture formation in the CNG engines. The second stage of the study was to investigate the mixture formation and fluid dynamic behavior of two different CNG injection systems: Multi-Point (MP) and Single-Point (SP) injection systems. The Injection system has been developed within the 0D-1D environment, GT-Power, and has been calibrated to match precisely the experimental data from static and dynamic test bench. The SP injection system retains a better balancing of air-to fuel ratio for different cylinders with respect to MP injection system for the steady state operations [Figure 1]. On the other hand, the MP injection system provides faster response to transient operations and minimizes the cylinder-to-cylinder variations in term of air-to-fuel ratio. Adopting advance control strategies such as injection timing optimization, injection rail pressure modulation (which has been developed in the first stage of the activity) and compensation strategy has improved the mixture formation and hence the engine performance.

Figure.1: Cylinder-to-Cylinder Lambda variation

for SPI and MPI systems for one steady state

point.

0.8

0.85

0.9

0.95

1

1.05

1.1

1.15

1.2

0 1 2 3 4 5 6 7

Lam

bd

a

Cyl. No.

800 RPM - 100%load

MPI

SPI

ECU Target


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First name: Danilo LAST NAME: LAURENZANO.

Topic: Control-oriented models for high efficiency flex fuel SI engines for the 2020+ targets.

Course year: 1st Tutor(s): E. Spessa, D. Misul.

Academic context [1] D. A. Misul, M. Baratta, H. Kheshtinejad, “Fluid-Dynamic Modelling and Advanced Control Strategies for a Gaseous-Fuel Injection System” SAE Paper 2014-01-1096 [2] F. Millo, C. V. Ferraro, “Knock in S.I. Engines: A Comparison between Different Techniques for Detection and Control” SAE Paper 982477, 1998 [3] L. Chen, T. Li, T. Yin, B. Zheng, “A predictive model for knock onset in spark-ignition engines with cooled EGR”, Energy conversion and Management, Volume 87, November 2014, Pages 946-955


CRF

Highlights of the research activity Bi-fuel engines have recently gained considerable importance. Therefore, the design and optimization of models are a trade-off between the characteristics of gasoline and methane. For the high efficiency flex fuel SI engines of the future, the goals will be different: it will be possible to have engine fueled only with natural gas. The research activity of this first year is focused on the behavior of the new elements. The ICE under investigation is a DISI engine with a high compression ratio, fueled only with methane. First of all the study on the injection system was carried out: typically the natural gas engine is PFI but in this case there is a direct injection. Hence the system was modeled on AMESim with specific attention to the pressure reducing valve because it strongly acts on the dynamic of the pressure in the rail. Since the injector works like a chocked nozzle the pressure oscillations impact on the mass flow rate. The ECU uses averaged quantities so it’s important to evaluate the mismatch between the estimations and the actual amounts of fuel injected. Due to the higher compression ratio (CR=13, useful to reach higher performance and efficiency), it is possible to incur into the problem of auto-ignition, well known as knock. The lack of information on the literature about the behavior of methane is due to its high octane number. The engine tests were carried out by the CRF on different operating conditions; first the cycles were analyzed to detect the knocking one by means of spectral analysis and knock indexes. Afterwards a predictive model with the capability to provide the knock onset was developed. In the future work the auto-ignition model will be calibrated and implemented in a GT-Power code.

Figure: Mass fraction burned

(xb) and ∫dt/τ (auto-ignition) for a

cycle. If the integral reaches the

unity before the xb , knock

occurs.


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First name: Arpit LAST NAME: MAHESHWARI

Topic: Innovative and ageing resistant Li-ion batteries for high electric energy storage in a smart grid framework

Course year:1st Tutor(s): M. Santarelli

Academic context [1] M. Doyle, T.F. Fuller, J. Newman, Modeling of Galvanostatic Charge and Discharge of the Lithium/Polymer/Insertion Cell, J. Electrochem. Soc. 140 (1993) 1526. doi:10.1149/1.2221597 [2] V. Srinivasan, J. Newman, Discharge Model for the Lithium Iron-Phosphate Electrode, J. Electrochem. Soc. 151 (2004) A1517. doi:10.1149/1.1785012 [3] C. Delacourt, M. Safari, Analysis of lithium deinsertion/insertion in LiyFePO4 with a simple mathematical model, Electrochim. Acta. 56 (2011) 5222–5229. doi:10.1016/j.electacta.2011.03.030


Lithops S.r.l, Turin, Italy

Fraunhofer ISE, Freiburg, Germany

Eindhoven University of Technology, Eindhoven, The Netherlands

Highlights of the research activity Lithium ion batteries are increasingly becoming important in the field of energy storage whether to power vehicles, for home/industrial electric energy storage or at a grid level to maintain the grid power quality. Their high efficiency, fast response and modular nature make such a wide range of applications possible. However cost, performance and safety are some challenges that this technology still faces. In this research, modelling is used as tool to understand how lithium batteries work and help design better and safer battery systems. A flexible physics based model of the battery pack is developed combining electrochemistry, heat transfer and fluid dynamics in order to simulate pack behaviour under different operating and environmental conditions. The modelling approach has been bottoms-up, starting with the level of single cell layers and moving subsequently to pouch cell, module and finally pack level. Appropriate reductions have been undertaken at all hierarchies in order to ensure that the final model of the pack is accurate but at the same time not too computationally expensive. This approach developed can be used to design and optimize battery systems at all levels of their hierarchy. Future research work will consist of combining this physics based model (more accurate) with an empirical model (faster) in order to develop a hybrid model. Moreover, integration of battery systems with grids will be studied and optimum strategies for grid connection will be identified. The model is developed and simulated using commercial software COMSOL Multiphysics® which uses the finite element method. The research work is conducted in the framework of MARS-EV (http://www.mars-ev.eu/) and CA(R)VOUR (http://www.carvour.it/) projects and has been funded through Erasmus Mundus Joint Doctoral Programme SELECT+, the support of which is gratefully acknowledged.

Figure: (top) Bottoms-up modelling approach.

(bottom) Temperature distribution in a pack (an example of pack

level simulation). Seen here is a liquid cooling circuit to regulate

temperature.

http://www.mars-ev.eu/

http://www.mars-ev.eu/

http://www.carvour.it/


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First name: Mohsen LAST NAME: MIRZAEIAN

Topic:. Numerical Simulation of the Cycle-to-Cycle Variation and

Knocking Phenomena in Spark Ignition Engines

Course year: Second Tutor(s): Federico Millo

Academic context [1] Millo, F., Rolando, L., Pautasso, E., Servetto, E.: “A Methodology to Mimic Cycle to Cycle Variations and to Predict Knock Occurrence through Numerical Simulation”, SAE Technical Paper 2014-01-0070, 2014 [2] Fontanesi S., D'Adamo A., Paltrinieri S., Cantore G., Rutland C., “Assessment of the Potential of Proper Orthogonal Decomposition for the Analysis of Combustion CCV and Knock Tendency in a High Performance Engine”, SAE Technical Paper 2013-24-0031, 2013 [3] Poetsch C., Schuemie H., Ofner H., Tatschl R., Vitek O., “A Computational Study on the Impact of Cycle-to-Cycle Combustion Fluctuations on Fuel Consumption and Knock in Steady-State and Drive cycle Operation”, SAE Technical Paper 2013-24-0030, 2013



FIAT Research Center

Argonne National Labs

Highlights of the research activity Although nowadays downsizing associated with turbocharging represents one of the most valuable options to reduce the CO2 emissions of automotive Spark Ignition (SI) engines, the search for continuously increasing boost levels has led to a dramatic increase of the knock likelihood, requiring quite often spark timing retards, mixture enrichment and/or compression ratio reductions which can jeopardize the expected CO2 emissions benefits. As a consequence, robust and reliable knock modeling becomes more and more important to support the design and calibration of modern high-performance, downsized and turbocharged SI engines. Experimental observations clearly show that SI engines are affected by a significant amount of Cycle-to-Cycle Variations (CCV) of cylinder pressure which is a common problem reducing performance due to variations in combustion phasing, and, in some circumstances, can lead to knocking. Therefore, as the application domain of the engine simulation models enters the full load conditions, the modeling of cyclic variations becomes increasingly important. The research has been focused on the development of a new 0-D turbulence model belonging to K-k and k- ε model family, which is capable to predict the in-cylinder flow parameters such as turbulent kinetic energy and integral length scale. Afterwards, a 1-D combustion model has been coupled with the above mentioned turbulence model in order to predict the burn rate at various operating points for the mean cycle. In the next step, the variability of different stages of combustion has been investigated and it has been confirmed that the first and second stages of combustion vary for subsequent cycles, hence it is not possible to reproduce CCV by means of the perturbation of a single combustion parameter. Future work will be devoted to coupling

the CCV model with a predictive knock model in order to predict the knock limited spark advance at high and full load

conditions, including the effects of the adoption of extreme Miller timings and of water injection to mitigate knock

likelihood.

CCV and knock prediction by coupling

the newly developed turbulence and

combustion models


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First name: Maria Pia LAST NAME: MONTEROSSI

Topic: Energy saving through an innovative aircraft turbine thermal control

Course year: XXX Tutor(s): Elena CAMPAGNOLI, Paolo MAGGIORE

Academic context [1] G.J.J. Ruijgrok, D.M. Van Paassen, 2007, “Elements of aircraft pollution”, Delft Academic Press. [2] S. Brack, Y. Muller: “Probabilistic Analysis of the secondary air system of a low-pressure turbine”, Proc. Of ASME Turbo Expo 2014, GT2014, 16-20 June 2014, Dusseldorf. [3] S.B.Lattime, B.M. Steinetz, “Turbine engine clearance control systems: current practices and future directions”, NASA / TM 2002-211794


Avio Aero

Highlights of the research activity The activities carried out during the first year have been mainly focused on the numerical analyses required to point out a suitable insulation methodology and can be summarized in the three following steps:

The available numerical model (fluid and thermal), used to predict the thermal behavior of one stage of a Low Pressure Turbine (LPT), has been tuned by using the data obtained during a previous experimental campaign carried out with the ThermalCase test rig facility. After the tuning procedure the numerical model has shown a good agreement with the experimental data satisfying the tolerance criteria usually set for the whole engine numerical models.

The previous matched model has been used to study and to compare different insulation configurations able to minimize the cooling air mass flow rate usually required to cool down the inner Case surface. The analyses have been carried out to choose the suitable insulation blankets number and position. With this aim two possible configurations have been examined: the first one obtained by using 3 blankets and the second one carrying 5 blankets (Figure 1). The numerical analyses have shown the set up obtained by using 5 blankets is able to exhibit better performances than the 3 blankets configuration. On the basis of this result, only for the 5 blankets configuration, a further analysis about the blankets sizes has been performed with the aim to point out a design solution able to preserve as much as possible the Test Article instrumentation. The numerical analysis has shown the blankets size, at least in the range of interest, has almost no effect on the temperature distribution.

The final design solution has been used to numerically forecast the effectiveness of the insulation methodology under different thermal condition in comparison with the case without blankets and to produce the blankets to be used for the testing phase.

Figure 5: Configurations: a) 3 blankets, b) 5 blankets

Figure 2: Allowed cooling mass flow rate reduction


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First name: Federica .LAST NAME: PAOLICELLI

Topic: Model-based control approaches for injection and combustion processes in diesel engines

Course year: 2nd Tutor(s): Ezio Spessa, Alessandro Ferrari

Academic context [1] Baur, R., Blath, J., Bohn, C., Kallage, F. et al., 2014, “Modeling and Identification of a Gasoline Common Rail Injection System”, SAE Technical Paper 2014-01-0196, 2014, doi: 10.4271/2014-01-0196. [2] Wagner N., Adhikari S., “Symmetric State-Space Method for a Class of Nonviscously Damped Systems”, AIAA Journal, Vol. 41, No. 5, May 2003. [3] Bendat, J.S., Piersol, A.G., 1993, “Engineering applications of correlation and spectral analysis”, John Wiley and Sons.


General Motors Powertrain Europe

Nanyue Fuel Injection Systems Co., Ltd


The enhanced control of the fuel injected quantities and of combustion evolution is one of the main concern

of modern common rail fuel injection systems. Different model-based and theoretical strategies can be

implemented in order to achieve these objectives. The control of complex systems, such as fuel injection

apparatus, can be supported by an optimized hydraulic layout of

the piping system and of the injectors. A proper design can

prevent hydraulic resonance phenomena, which alter the system

performance. In the perspective of a control-oriented design

approach, modal analysis is an useful tool to deeply examine the

dynamic behavior of the injection system and to improve the

response to pressure waves, which represent an issue for the

pressure control system efficiency. The modal analysis allows the

main modes of vibration to be identified and consequently to

determine the most stressed system components and their

optimal design. It is also possible to apply the modal analysis to

investigate the influence that some key geometrical parameters

can have on flow-rate and pressure time histories along the high

pressure circuit. The numerical model, which has been used for

the modal analysis, can finally be implemented to develop

transfer functions that can improve the accuracy of the injection

apparatus control system.

Other relevant aspects that can impact on the control of the injection system are related to the injector static

leakages and to the rail volume. The reduction in the static leakage of high-pressure injectors generally

promotes the adoption of advanced and innovative control strategies. On the other hand, the current trend of

progressively reducing the rail volume could represent an issue for the improvement of the control system

performance.

Comparison between numerically evaluated

eigenfrequencies and single-side power

spectrum of a pressure trace detected at the

injector inlet.

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

f [kHz]

0.0

0.2

0.4

0.6

0.8

1.0

S /

S0

[-]

Experimental signal

Numerical frequency

0.66

0.83

2.25


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First name: Benedetta LAST NAME: PEIRETTI PARADISI

Topic: Proton acceleration by laser-matter interaction for oncology radiotherapy

Course year: 1st Tutor(s):Gianni COPPA

Academic context [1] E. Boella, B. Peiretti Paradisi, A. D’Angola, G. Coppa and L. O. Silva, “Study on Coulomb explosions of ion mixtures” submitted to Journal of Plasma Physics, 2015 [2] Hohenberger et al, “Dynamic acceleration effects in explosions of laser-irradiated heteronuclear clusters” Physical Review Letters, vol. 95, pp. 195003, 2005 [3] A. D'Angola, E. Boella and G. Coppa “On the applicability of the collisionless kinetic theory to the study of nanoplasmas” Physics of Plasmas, vol 21, pp. 82116, 2014


• Instituto Superior Tecnico, Lisbon, Portugal (Prof. Luis O.Silva) • Università della Basilicata (Prof. Antonio D’Angola)


Coulomb explosion dynamics of spherical nanoplasmas composed by two different ion species has been studied [1]. In fact, it has been verified that in the presence of ion mixtures, there are conditions that allow for a quasi-monoenergetic distribution of the species having the larger charge-to-mass ratio (fast ions) [2], a fundamental characteristics for biomedical applications. The connection between the formation of shock shells during the explosion and the monochromaticity of the ion spectrum has been supported by a detailed analysis, showing that under particular conditions the width of the asymptotic energy spectrum tends to become very narrow, with all the ions having nearly the same kinetic energy, which leads to a multi-valued ion phase-space. In particular, in the limit case of slow ions at rest, the energy spectra tends to a Dirac delta (Fig. 1). The conditions to generate a quasi mono-energetic ion spectrum have been rigorously demonstrated and verified by numerical simulations, using the so-called “shell method” [3] a technique that, exploiting the spherical symmetry of the problem, allows to obtain very accurate and precise results. The novelty of this research may be summarized in the following points:

• An extended theoretical analysis of the fundamental physical mechanisms of the Coulomb explosion of ion mixtures is performed, with particular interest to the energy spectrum of the component with the larger charge-to-mass ratio. Carbon-Hydrogen clusters have been considered, with different degree of ionization of the Carbon species.

• A simple way to deduce if overtakings between fast ions take place during the expansion is presented and discussed and it is proved rigorously that the appearance of shocks depends only on the ratio between the total charge of the fast ions with respect to the one of the slow ions, and not on their masses. In particular, by using a Hamiltonian approach the existence of a threshold for the mixture composition above which no shocks are forming, is provided.


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First name: Andrea LAST NAME: PIANO

Topic: Advanced air management systems for future automotive diesel engine generations

Course year: 1st Tutor(s): F. Millo

Academic context [1] Zammit, J.P., McGhee, M.J., Shayler, P.J. , Law, T., Pegg, I., “The effects of early inlet valve closing and cylinder disablement on fuel economy and emissions of a direct injection diesel engine”, Energy, Volume 79, 1 January 2015, Pages 100-110, ISSN 0360-5442, http://dx.doi.org/10.1016/j.energy.2014.10.065 [2] Lancefield, T., "The Influence of Variable Valve Actuation on the Part Load Fuel Economy of a Modern Light-Duty Diesel Engine," SAE Technical Paper 2003-01-0028, 2003, doi:10.4271/2003-01-0028 [3] Millo, F., Mallamo, F., Arnone, L., Bonanni, M. et al., "Analysis of Different Internal EGR Solutions for

Small Diesel Engines," SAE Technical Paper 2007-01-0128, 2007, doi:10.4271/2007-01-0128



Powertech Engineering


Highlights of the research activity The increasing stringency of pollutant emissions regulations is expected to foster the implementation of new technologies regarding aftertreatment, air management and fuel injection systems. For these reasons, in the modern automotive diesel engines it is common to find electronically-controlled flexible fuel injection system, air/EGR (Exhaust Gas Recirculation) control valves and Variable Geometry Turbine (VGT) to regulate the gas flow. Then, a fully flexible Variable Valve Actuation (VVA) system is becoming highly desirable. The support of simulation models is crucial for the optimization of such complex systems that cannot be performed only via experimental approaches. In this context, firstly, a detailed diesel engine model was calibrated and validated by means of a commercially available 1D CFD software, GT-SUITE. This engine model, with the integration of a detailed injector model, uses a predictive combustion model making it a virtual test bench where evaluating the VVA potential. Then, a proper k-points evaluation was done: the NEDC (New European Driving Cycle) and WLTP (Worldwide harmonized Light vehicles Test Procedures) cycles were analyzed to highlight the most representative engine operating conditions where considering the VVA integration. Lastly, once a DoE process methodology has been implemented, several techniques were tested accounting the impact between a step mechanization or a continuous one. The results in terms of performance and capabilities of the VVA technology were quantified according to the efficiency, emissions and exhaust temperature after turbine.

GT-SUITE detailed engine model –

Exhaust phasing technique results


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First name: Pietro LAST NAME: PIZZO

Topic: Development of innovative diagnostic tools for fuel injection systems (FIS) and design of new measurement devices for hydraulic test benches

Course year: 3rd Tutor(s): A.Mittica, A. Ferrari

Academic context [1] Lino P., Maione B., Rizzo A., “Nonlinear modelling and control of a common rail injection system for diesel engines”, 2005, Applied Mathematical Modelling, Vol.31, Issue 9, p. 1770-1784. [2] Tan X. G., Sang H. L., Qiu T., Fan Z. Q., Yin W. H., “The impact of Common Rail System’s Control Parameters on the Performance of High-power Diesel”, 2012 International Conference on Future Energy, Environment and Materials, Energy Procedia 16(2012) 2067-2072. [3] Gauthier C., Sename O., Dugard L., Meissonnier G., “Modelling of a Diesel engine common rail injection system”, 2005, Proceedings of the IFAC World Congress, Vol. 16, Part 1.


Rabotti s.r.l.

Kistler Italia s.r.l.

National Instruments Italy s.r.l.

Highlights of the research activity The activity of the first two years has been focused on the development and optimization of an algorithm for the evaluation of the instantaneous flowrate in high-pressure pipes on the basis of the measurement of the pressure time histories at two locations of a pipeline. The algorithm has been implemented in a flowmeter prototype (FLOTEC). The activity of 3

rd year has been focused on the development of a user interface using

Labview and on a further optimization of the flowmeter by means of a stepwise calibration of two pressure sensors in order to reduce the uncertainty and thus improve the evaluation of the flowrate. Furthermore, some relevant applications of the flowmeter have been studied. In particular, the flowmeter algorithm has been used to validate a numerical model of a Common Rail (CR) high-pressure pump in order to analyze the pump flow-rate ripple and the effect of the pump head on the pump delivered flow-rate time history. Then, the pump delivered flow-rate traces obtained from the flowmeter has been used also to optimize a submodel of CR injection apparatus pressure control system. The aim of the activity has been the development of a fully predictive model of the whole injection system, which includes, the rail, the injectors, the piping system and the pressure control subsystem. This model can be used to investigate the impact of different control strategies and of the pump dynamic behavior on the injection system performance. Finally, the flowmeter has been applied to an hydraulic power-system test-bench that is aimed at analyzing the dynamic response of hydraulic servo-valves. In this case, the flowmeter is applied to check the methodology followed for testing the valve and to validate a model of the servo-valve and the hydraulic actuator connected to the valve.

Figure 6. screenshots of the FLOTEC user interface.


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First name: Alberto LAST NAME PIZZOLATO

Topic: Topology optimization for energy problems

Course year: 1st Tutor(s):Vittorio Verda, Adriano Sciacovelli

Academic context [1] Alexandersen, J., Aage, N., Andreasen, C. S., & Sigmund, O. (2014). Topology optimisation for natural convection problems. International Journal for Numerical Methods in Fluids, 76(10), 699-721.Energy, 33(9), 2337-2354. [2] Bendsøe, M. P., & Sigmund, O. Topology optimization: theory, methods and applications. 2003. [3] Kreissl, S., Pingen, G., & Maute, K. (2011). Topology optimization for unsteady flow. International Journal for Numerical Methods in Engineering, 87(13), 1229-1253.


Kurt Maute, University of Colorado, Boulder CO, USA

Joe Alexandersen, Technical University of Denmark (DTU), Lyngby, Denmark

Highlights of the research activity As the global fossil fuel supply is rapidly shrinking, there is a growing need of devices and systems that utilize energy in an efficient, reliable and conservative way. Therefore, many researchers are focusing on the development of more and more powerful methodologies for the energetic performance maximization during the design phase. In this framework, topology optimization has emerged as one of the most powerful tools to generate innovative designs, which most often leads to unexpected topologies, shapes and configurations. However, besides its widespread adoption in the field of structural mechanics, multi-physics applications of this method are still in their early days. The aim of this PhD research is to explore and extend the utilization of this methodology to the optimization of devices and systems that involve heat transfer and fluid flow. Based on the core expertise of the research group, we have selected three demonstrative applications:

1. The optimization of high conductivity material distribution for heat transfer enhancement in Phase Change Material storage tanks (on-going)

2. The optimization of the nodes connectivity in district heating networks for increased robustness and reliability (planned)

3. The optimization of an electronics heat sink for minimization of the heat transfer resistance (planned)

The past year has been dedicated to the development of Application 1. As a first approximation, we considered 2D steady-state diffusion with uniform heat generation and, to drive the designs towards optimal heat transfer performances, we have set the global thermal resistance as objective function. Sensitivities are computed by solving a discrete adjoint problem. Results show that the topological design reduces the maximum overheating of roughly 84 %. In fact, compared to a previous design obtained by a response surface optimization with 5 shape parameters, it brings the maximum temperature down from the original 489 K to 324 K. On-going activities are focused on the investigation of the full transient problem: we aim at assessing how the optimal design is affected by the melting characteristics of the PCM. To our best knowledge, this has never been done before.

Figure 1- a) Graphical abstract of

Application 1. b) Optimized topology c) Optimized performance


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First name: Mahsa LAST NAME: RAFIGH

Topic: Diesel Engine Modelling For Efficient Calibration.

Course year: Second Tutor(s): Federico Millo

Academic context [1] Mallamo, F., Millo, F., Rolando, L.: “Model-based development and calibration of last generation diesel powertrains for passenger cars”, Int. J. Powertrains, Vol. 3, No. 1, 2014 [2] Forzatti, P., Lietti, L., Nova, I., Tronconi, E., "Diesel NOx aftertreatment catalytic technologies: Analogies in LNT and SCR catalytic chemistry," Catalysis Today, vol. 151, no. 3-4, pp. 202-211, June 2010, DOI: 10.1016/j.cattod.2010.02.025, http://dx.doi.org/10.1016/j.cattod.2010.02.025. [3] Wehinger, G.D., Eppinger, T., Kraume, M., Fluidic effects on kinetic parameter estimation in lab-scale catalysis testing – A critical evaluation based on computational fluid dynamics, Chemical Engineering Science, Volume 111, 24 May 2014, Pages 220-230, http://dx.doi.org/10.1016/j.ces.2014.02.025




RWTH Aachen University, ACA (Center for Automotive Catalytic Systems Aachen)

Highlights of the research activity The optimization of complex aftertretament systems for modern automotive diesel engines cannot be

performed purely relaying on experimental approaches, but has to be supported by relaible and

computationally efficient simulation models. In this context, a diesel aftertreatment models was built by

means of a commercially available 1D CFD software, GT-Power. The model was then calibrated and

validated with experimental data which were gathered in collaboration with the ACA of RWTH University,

including light-off, oxygen storage capacity, and NOx storage and

reduction experiments using synthetic gas bench on a reactor

scale catalyst component. The simulation results showed a good

agreement with experimental data concerning NOx conversion

efficiency, CO and HC light-off. Afterwards, the reactor scale

model was scaled-up to the full size aftertreatment component and

assessed over the WLTC. In the second phase of the research,

the performance of SCR coated on a Diesel Particulate Filter

(SCRf) was analyzed. Experimental activity including NO oxidation,

temperature program desorption (for assessment of NH3

adsorption), and temperature program reduction (for assessment

of different SCR reactions) for different soot loading levels were

performed on reactor scale component again at RWTH. Then, a

global kinetic mechanism was implemented in the model and was

calibrated according to experimental data. In future activity, the

calibrated model will be scaled up to full scale component to

assess it efficiency over different driving cycles using single

SCR/LNT or in combination. The innovative contribution expected will be the assessment, through a new

comprehensive numerical model of the whole powertrain system, including the aftertreatment, of the more

promising technology mix to reach the future challenging emissions and fuel economy targets for diesel

powertrain for passenger car applications.

Development of the aftertreatment model

from reactor to full Scale over WLTC


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First name: Laura LAST NAME: RIETTO

Topic: Energy systems integration: from building scale to urban scale

Course year: 3rd Tutor(s): G.V. Fracastoro, V. Verda

Academic context [1] A. Dalla Rosa, J.E. Christensen , Low-energy district heating in energy-efficient building areas. Energy, Volume 36, Issue 12, December 2011, Pages 6890-6899. [2] A. Dalla Rosa, R. Boulter, K. Church, S. Svendsen, District heating (DH) network design and operation toward a system-wide methodology for optimizing renewable energy solutions (SMORES) in Canada: A case study. Energy, Volume 45, Issue 1, September 2012, Pages 960-974. [3] Henrik Lund, Sven Werner, Robin Wiltshire, Svend Svendsen, Jan Eric Thorsen, Frede Hvelplund, Brian Vad Mathiesen, 4

th Generation District Heating (4GDH): Integrating smart thermal grids into future

sustainable energy systems. nergy, Volume 68, 15 April 2014, Pages 1-11


IREN S.p.A.

Universidad de Mendoza. Facultad de Arquitectura, Urbanismo y Diseño

Regione Piemonte - IISBE Italia - CTI Group 213 (energy audits)

Highlights of the research activity The research activity of my PhD this year focuses on the simulation of a small urban district from the thermal energy point of view. The main goal of my work is to assess the possible energy savings of the buildings and how their energy demand reduction may affect the operation of a urban district heating network (DHN). The single models of the buildings allow to operate on different features of the buildings such as the envelope or the characteristics of the heating systems or their management parameters. In this way it is possible to evaluate the impact of different energy saving measures that may be adopted, from the modifications of some construction element to the variation of the temperature and operation settings of the thermal system. Nevertheless the global impact may be different depending on the position of the building and the operation at a district level. Five case studies of the Crocetta neighborhood of Torino, all of them connected to the urban district heating system, are being modeled within the EnergyPlus environment: two residential buildings, a kinder-garden, a primary school and an office building. These buildings were selected in order to have a reference for energy consumption in buildings connected with the DHN characterized by different use. In all these buildings indoor temperature sensors were recently installed while the operation data of the heating systems were provided by Iren S.p.A. These data are now used to validate the models in order to get reliable energy demand profiles and temperatures. The output data of the detailed dynamic simulations are being used as input for a neural network, with the aim of predicting the possible effects of variations in the thermal demand profiles of the buildings on the internal temperatures, without the need of launching time-consuming dynamic simulations. This type of model will thus be integrated in a district heating model in order to perform the optimization of thermal demand profiles of the building at an overall system level.

Figure 1 - Energy model of the

kinder-garden case study (building-

system-results)

http://www.sciencedirect.com.ezproxy.biblio.polito.it/science/article/pii/S0360544211006608








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First name: Fabio LAST NAME: SABA

Topic: Towards the development of a National Standard for Thermal Energy and its application to smart heat meter calibration

Course year: 3rd Tutor(s): Prof. Marco Masoero, Dr. Vito Fernicola

Academic context [1] K. Tawackolian, O. Büker, J. Hogendoorn, T. Lederer, “Calibration of an ultrasonic flow meter for hot water”, Flow Measurement and Instrumentation, vol. 30, pp. 166-173, 2013. [2] F.J. Weber, W.W. Durgin, H. Johari, “Ultrasonic Beam Propagation in Turbulent Flow”, Proceedings of ASME FEDSM’01, New Orleans, Louisiana, May 29-June 1, 2001 [3] K. Tezuka, M. Mori, S. Wada, M. Aritomi, H. Kikura, Y. Sakai, “Analysis of Ultrasound Propagation in High-Temperature Nuclear Reactor Feedwater to Investigate a Clamp-on Ultrasonic Pulse Doppler Flowmeter”, Journal of Nuclear Science and Technology, 45:8, pp. 752-762, 2008.


INRIM (Istituto Nazionale di Ricerca Metrologica)

PTB (Physikalisch-Technische Bundesanstalt)

KROHNE Messtechnik GmbH

Highlights of the research activity During the 3

rd PhD year, my research activity has been focused on the metrological characterization of the

repeatability, stability and reproducibility of the new INRIM Thermal Energy Standard, the realization of a transfer heat meter for a bilateral comparison between INRIM and PTB (German National Metrological Institute) thermal energy standards and the cooperation with the Heat and Vacuum Department of PTB for studying and designing a non-intrusive ultrasonic sensor for the simultaneous measurement of liquid flow rate and temperature. My 3

rd year research activity is further detailed below:

the INRIM Thermal Energy Standard, which was significantly renewed and modified in the last five years, has been characterized in terms of measurement repeatability, stability and reproducibility; a suitable design of experiment has been performed in order to take into account all the main influencing factors and the most critical parameters which affect the measurement of thermal energy and its uncertainty;

a transfer heat meter characterized by high repeatability and stability has been assembled in cooperation with PTB and KROHNE in order to compare INRIM and PTB thermal energy standards; it basically consists of a magnetic flow rate meter with a suitable entrance length and a pair of long stem platinum resistance thermometers, calibrated as a single sensor for accurate temperature difference measurements;

the study and design of an innovative non-intrusive ultrasonic sensor for the simultaneous measurement of liquid flow rate and temperature has started since October 2015 in the context of a joint research activity with the Heat and Vacuum Department of PTB in Berlin, where I’m working as guest PhD student; a model of the ultrasonic transit-time sensor has been developed to describe its behaviour in a specific range of flow rate and temperature, to identify the most important parameters and assumptions affecting the accuracy of the sensor and, finally, to improve its measurement capabilities.

Effect of water temperature (from 110 °C to

250 °C) on the refraction of ultrasound

beams in a transit time clamp-on sensor


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First name: Mahrokh LAST NAME: SAMAVATI

Topic: Design and analysis of SOEC-based systems for synthetic liquid fuels production

Course year: 2nd Tutor(s): Massimo Santarelli

Academic context [1] Becker, W.L., Braun, R.J., Penev, M., Melaina,M., “Production of Fischere-Tropsch liquid fuels from high temperature solid oxide co-electrolysis units”, Energy, 2012; 99-115 [2] Graves, C., Ebbesen, S.D., Mogensen, M., Lackner, K., “Sustainable hydrocarbon fuels by recycling CO2 and H2O with renewable or nuclear energy”, Renewable and sustainable energy reviews, 2011; 15: 1–23 [3] Jensen, S.H., Sun, X., Ebbesen, S.D., Knibbe, R., Mogensen, M., "Hydrogen and synthetic fuel production using pressurized solid oxide electrolysis cells." International Journal of Hydrogen Energy, 2010; 9544-9549


Department of Energy Technology, Royal Institute of technology (KTH), Stockholm, Sweden

Highlights of the research activity One of the biggest challenges of renewable energy sources like solar is their incapability of meeting the user

demands at all the time due to their intermittent nature. This issue can only be solved by employing some

type of energy storage that stores the excess power when it is available for further usage, e.g. during the

peak hours. It is more or less inefficient and even impossible to store very large quantities of electricity;

consequently it has to be transformed into other forms of energy carriers which are more suitable for storage

as an example in the form of chemical energy of mass streams, also known as Chemical Energy Storage

(CES). The main objective of this project is to develop a pathway for power to liquid. This is considered to be

done through design and optimization of integrated system consisting of RES-fed solid oxide electrolyser,

entrained flow gasification, Fischer-Tropsch (FT) reactor and syncrude refining system. The target end

products are FT gasoline and Diesel

Solid oxide electrolysis cells can be used to convert the excess generated electricity into chemical energy via simultaneous electrolysis of steam and carbon dioxide. Electrolysis cells are modular devices which are simple, performing the dissociation in a single step without need of any moving part, and producing and releasing the products separately in the anode and cathode compartments of the cell. In addition, the electrolysis process is immediate use of renewable energies to produce the syngas precursor of a synthetic liquid fuels. The electrolyser system (Figure 1) was analyzed according to the first and second laws of thermodynamics. According to the achieved results it may be more beneficial to operate at atmospheric pressure rather than elevated pressures due to the effect of methanation when production of other hydrocarbons is the target. A journal paper is prepared and under review by supervisors.

Figure 3- Schematic of Solid oxide Electrolyser system


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First name: Gianluca LAST NAME: SERALE

Topic: Getting closer the mismatch between RES availability and exploitation

Course year: I Tutor(s): Prof. Marco Perino, Prof. Alfonso Capozzoli

Academic context [1] Serale et al. (2015). Design of a low…Material (PCS). Energy and Buildings, 106, 44-58.

[2] Fiorentini et al. (2015). Development and … house. Energy and Buildings, 94, 21-32.

[3] Yu et al. (2013). Extracting knowledge … framework. Building Simulation , 6, No. 2, 207-222.


Prof. Francesco Goia - Norwegian University of Science and Technology, Trondheim, Norway

Prof. Alberto Bemporad – IMT Instute of Advanced Studies, Lucca, Italy

Prof. Per Heiselberg – AAU, Denmark

Highlights of the research activity The adoption of Renewable Energy Sources (RES) can mitigate the footprint of the building sector. However, the full profitability of RES is often limited to a great extent by the time mismatch between their availability and energy demand of buildings and consumers. For this reason energy storage strategies and adaptive control logics are required, to partially mitigate this gap between availability and exploitation of RES. Comparing the potentialities offered by active and passive thermal energy storage in building is an important issue to fulfill RES integration. The active thermal storage consists into the adoption of storage tanks in which thermal energy is accumulated taking advantage of sensible or latent heat. The passive thermal storage consists, instead, in the exploitation of the building features themselves, such as the building thermal inertia due to the envelop, to reduce peak loads and to maintain environmental conditions in the thermal comfort range. In order to take advantage of RES both these aspects should be considered and their combination should be coupled and optimized. On one hand, technologies useful to increase the performance of active storage systems coupled with RES are being studied. In particular, a solar thermal system based on latent heat storage Phase Change Materials (PCMs) is being tested through a real scale prototype. During the first year of this PhD the control strategies and the measuring system of the prototype were set up. A first series of experiments has been carried out. These tests allowed to validate a numerical model and compare the performance against a reference water based solar thermal system. Moreover, some experimental activities for the performance characterization of PCMs were carried out. On the other hand, a deep literature review was done to define the existing methods for optimizing the combination of active and passive storage strategies. Firstly, data driven techniques were analyzed as an optimal way to manage big amount of experimental data, with the aim to perform an high level energy optimization. Secondly, predictive control algorithms were analyzed as possible tools capable of optimizing at low level the building energy performance. A particular attention has been paid to receding horizon methods (e.g. Model Predictive Control). The application of high and low levels building energy optimization integrated into building automation systems will be one of the future step to be analyzed in this research activity.

PCM-based solar thermal system

prototype on DENERG roof.


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First name: Roberto… … LAST NAME: TAURINO

Topic: Energy-efficient innovative seal for aircraft engines

Course year: 3rd Tutor(s): Elena Campagnoli (DENERG), Paolo Maggiore (DIMEAS)

Academic context [1] J. Denecke, K. Dullenkopf, S. Wittig and H.-J. Bauer, Experimental Investigation Of The Total Temperature Increase And Swirl Development In Rotating Labyrinth Seals Asme Turbo Expo 2005: Power for Land, Sea and Air June 6-9, 2005, Reno-Tahoe, Nevada, USA [2] K. Willenborg, V. Schramm, S. Kim and S. Wittig, Influence of a Honeycomb Facing on the Heat Transfer

in a Stepped Labyrinth Seal J. Eng.Gas Turbines Power 124(1), 133-139 (Feb 01, 2000) (7 pages)

[3] J. Denecke, V. Schramm, S. Kim and S. Wittig, Influence of Rub-Grooves on Labyrinth Seal Leakage J. Turbomach. 125(2), 387-393 (Apr 23, 2003) (7 pages)


GE Avio S.r.l.

Highlights of the research activity In the third year, the carried out research work was focused on the experimental activity. The selection of the innovative cell shapes was performed above all numerical investigated solutions. Leveraging on CFD results all geometries characterized by tendentiously rhomboidal stretched shapes have been selected. An experimental test has been carried out on a rhomboidal cell shape with proper dimensions in order to investigate the thermal behavior of the innovative solution. The test was performed on test rig facility managed by our Research Group that is available in the Energy Department of the Politecnico di Torino. The test rig was built in the frame of Great 2020 program and is able to reproduce the outer band static part of a low pressure turbine stage and the blade tip labyrinth seal. It works at high temperature and has been sized respecting the similitude of non-dimensional numbers ruling main thermal phenomena characterizing LPT turbine main flow path. The test article has been designed embedding the properly scaled innovative cells into the complete stepped shroud design. The part has been manufactured by means of Direct Metal Laser Sintering technique in Cobalt Chromium Alloy. Air and metal temperatures as well as air pressures have been monitored during the high temperature test. The measurements have highlighted that the increase of the total internal cell surface respect with the standard honeycomb determines an acceptable increase of the heat transfer from the flow path through the turbine casing. Moreover the same geometry has been flow tested on a static rig, available at GE Avio S.r.l., to validate the sealing performance increase highlighted by the numerical results. The test rig works at ambient temperature and reproduces a two fins straight labyrinth seal geometry. The test samples have been manufactured by means of DMLS technique at the engine scale. The tests campaign was focused both on standard and innovative solutions by measuring the discharge flow functions. Test data have confirmed the mass flow reduction trend that characterizes the innovative solution.

Low pressure turbine stage test

article cross section. In the yellow

box the labyrinth seal shroud tested

is highlighted.


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First name: Raffaella LAST NAME: TESTONI

Topic: Modelling of radionuclide transport in environmental matrices for Safety Assessment studies

Course year: 3rd year Tutor(s): Prof. M. De Salve and R. Levizzari (ENEA)

Academic context [1] Jakimaviciute-Maseliene, V., and Cidzikiene, V., 2015. Modelling of tritium transport in the underground water from hypothetical reactor at the new NPP site in Lithuania. Progress in Nuclear Energy, 80,1-6. [2] Twarakavi, N. K. C., Šimůnek, J. and Seo, H. S., 2008. Evaluating interactions between groundwater and vadose zone using HYDRUS-based flow package for MODFLOW. Vadose Zone Journal, 7(2), 757-768. [3] Xie, J., Lu, J., Zhou, X., Wang, X., Li, M., Du, L., Liu, Y., Zhou, G., 2012. Plutonium-239 sorption and transport on/in unsaturated sediments: comparison of batch and column experiments for determining sorption coefficients. Journal of Radioanalytical and Nuclear Chemistry, 296(3), 1169-1177.


ENEA

Highlights of the research activity The research topic are Safety Assessment (SA) studies, which aim to properly foresee and manage the environmental impact of nuclear activities. Safety Assessment mainly relies on detailed site characterization, in order to collect data to be processed with a suitable software (e.g. Modflow, Hydrus, HP1, PHREEQC) and predict the evolution of the potential contamination, and to investigate the environmental impact of analyzed activities. The work developed in this year consists of three main topics: - radionuclide transport in shallow groundwater: the source term was analyzed as the key point in the modelling of the transport of radionuclides in groundwater and soil. A methodological approach, which focuses on the dynamic of the source term in space and time, was applied. - Coupling of unsaturated zone and saturated zone model: in the management of radionuclide release in the environment, the unsaturated zone could be a natural barrier to delay or to stop the radionuclide migration through the environment and to protect the groundwater from contamination risks. A model that involves the interactions between the unsaturated zone and the saturated zone both from hydrogeological and radionuclide transport point of view was proposed (Fig.1). - Introduction of geochemical aspects: to improve the radionuclide transport model, geochemical aspects should be introduced. A research activity on the interaction between specific radionuclides and solid matrix in the unsaturated zone is ongoing. These activities, and those ones performed during 1

st and 2

nd year (characterization of the unsaturated zone

and saturated zone, and investigation of critical scenarios) were focused on the development of a preliminary SA study of the Italian nuclear site of Saluggia (VC). The research activity, developed in these three years, and that will be discussed in my PhD thesis, can support SA studies of nuclear facilities/activities.

Fig. 1 Flow chart of the proposed method to

couple the unsaturated zone and the

saturated zone both from hydrogeological

and radionuclide transport point of view.


51 | P a g e

First name: Yifei LAST NAME: TONG

Topic: CO2 Reduction Technologies for ICEs

Course year: 3rd Year Tutor(s): Mirko Baratta, Ezio Spessa

Academic context [1] M, Baratta., A.E, Catania., E, Spessa., A, Vassallo., (2005) Flame Propagation Speed in SI Engines: Modeling and Experimental Assessment. Proceedings of the ASME 2005 Internal Combustion Engine Division Fall Technical Conference ICEF2005, ICEF2005-1216 [2] M, Baratta., A.E, Catania., E. Sepssa., A, Vassallo., (2006) Development and assessment of a Multizone Combustion Simulation Code for SI Engines Based on a Novel Fractal Model. SAE Technical Paper 2006-01-0048 [3] Baratta, M., Tong, Y., Misul, D., Finesso, R., Spessa, E., “Advanced combustion and turbocharging management in a HD CNG engine for catalyst thermal operation optimization”. Paper under preparation, to be submitted to Journal of Natural Gas Science and Engineering.


Centro Ricerche Fiat

Metatron Spa

JRC

Highlights of the research activity Activities were carried out mainly through the CORE(CP, EU VII FP) project. The work mainly dealt with the cursor 8, CNG engine which has its compression ratio 11.5, total displacement 7.8 liter and waste-gate controlled turbocharging system. It was numerically analyzed using the 0/1D simulation code GT-Power. Transient analysis about the WHTC (Worldwide harmonized Heavy duty Transient Cycle) has been

simulated and assessed with the advanced combustion management aiming at optimizing the catalyst

system working condition by increasing its temperature. The modeling work has been performed with EIVC

mode. A period of WHTC (from 255th second to 260

th second)

was selected during which the engine speed and brake torque

increase. Especially the brake torque has a very sharp

increment. Relative test data about WHTC is supported by Fiat

Research Center. The results showed that an enhancement of

the catalyst warm up can be obtained by a proper

management of the combustion phase. By retarding the

combustion, the exhaust temperature could be increased

accordingly. Combustion modelling work has also been

conducted with this engine in order to substitute the WIEBE

combustion approach previously adopted in the GT-Power

model. The aim was to improve the model’s robustness and

predictability. The modelling approach was mainly based on the

fractal geometry concepts, as well on a suitable formulation for

the laminar burning speed. The model has thus become a predictive model, and allows the combustion

process to be reproduced with reasonable accuracy, thus reducing the need for experimental data.

Figure 4 Comparison between

predicted pressure and experimental

pressure


52 | P a g e

First name: Luigi LAST NAME: Ventola

Topic: High-efficiency heat transfer devices by innovative manufacturing techniques

Course year: 3rd Tutor(s): Pietro Asinari, Eliodoro Chiavazzo

Academic context [1] Neugebauer, R., Muller, B., Gebauer, M. and Toppel, T.; Additive manufacturing boosts efficiency of heat transfer components, Assembly Automation, 2011, 31:4, 344-347. [2] Wong, M., Owen, I., Sutcliffe, C.J. and Puri, A.; Convective heat transfer and pressure losses across novel heat sinks fabricated by Selective Laser Melting, 2009, 51:1-2, 281-288. [3] Ventola, L., Robotti, F., Dialameh, M., Calignano, F., Manfredi, D., Chiavazzo, E. and Asinari, P.; Rough surfaces with enhanced heat transfer for electronics cooling by direct metal laser sintering. International Journal of Heat and Mass Transfer, 2014, 75,58–74.


Center for Space Human RoboticsIIT@Polito, Istituto Italiano di Tecnologia, Turin, Italy.

MicrolaOptoelectronics S.r.l., Localita Baraggino 10034 Chivasso, Turin, Italy.

Denso thermal systems S.p.A., frazione Masio, 10046, Poirino, Turin, Italy.

Highlights of the research activity Third year of PhD research activity has been spent in investigating novel heat transfer devices with enhanced heat transfer performances [1, 2]. The devices have been designed by fully exploiting the capabilities of additive manufacturing (i.e. 3D printing) in fabricating, in one step, complex shaped metal (namely aluminum alloy) components, which could not be obtained by traditional manufacturing processes. The complex shapes of those devices allow to induce fluid-dynamic structures (vortexes, secondary flows), hence achieving augmentation in overall heat transfer transmittance. The latter is due both to enhanced heat transfer surface area and to enhanced convective heat transfer coefficient [3]. In particular, a novel heat transfer device based on ''Pitot tube'' principle (Pitot heat sink) has been developed: a traditional plate fin heat sink has been transformed by (i) introducing cavities in the fins, (ii) adding a stagnation pressure tap on the fins' top and (iii) static pressure taps on the wall of the hollow fins. Thanks to this configuration, the Pitot tube principle is exploited to induce secondary flows perturbing the main flow field, breaking boundary layers, and - consequently - enhancing heat transfer. Experiments show up to 95% increase in thermal transmittance of this heat sink respect to standard one. Another novel heat transfer device, based on ellipsoidal micro pins arranged in a hierarchical way on traditional plate fins, has been developed (see figure). Here, micro pins act as turbulators, generating shedding vortexes that perturb boundary layer and enhance convective heat transfer coefficient. Enhancement in thermal transmittance up to 32% of that hierarchical heat sink has been demonstrated experimentally. The results obtained in this research work shed light on the new frontiers that additive manufacturing are opening in heat transfer engineering. The extreme geometrical flexibility as well as variety of morphologies and shapes unlocked by additive manufacturing are expected to lead to a new way in conceiving and designing novel and highly efficient heat transfer devices.

Figure: Hierarchical heat sink


53 | P a g e

First name: Ludovico LAST NAME: VIGLIONE

Topic: Analysis of injection, mixture formation and combustion processes for

innovative CNG Engine

Course year: XXIX Tutor(s): Baratta Mirko- Misul Daniela

Academic context [1] O Colin, A Benkenida,. and C Angelberger,. (2003) A 3D Modeling of Mixing, Ignition and Combustion Phenomena in Highly Stratified Gasoline Engines. Oil & Gas Science and Technology, Rev. IFP, 58, 1, 47-62. [2] Baratta, M., and Rapetto, N., “Fluid-dynamic and numerical aspects in the simulation of direct CNG injection in spark-ignition engines”, Computers & Fluids 103, November 2014, Pages 215-233. [3] Baratta M ,Misul D., Viglione L, “Turbulence and combustion modeling in a high-performance, high- CR NG engine”- submitted to ASME-ATI-UIT 2015 Conference on Thermal Energy Systems: Production, Storage, Utilization and the Environment 17 – 20 May, 2015, Napoli, Italy.


CRF

AVL List Gmbh

Delphi

Highlights of the research activity The work is aimed to the analysis of fuel mixing and combustion in a high performance engine fuelled with compressed natural gas. The first part of the work was related to the combustion analysis under homogeneous condition. Such a study has been carried out by applying the ECFM-3z combustion model implemented in the Star-CD commercial CFD tool. A change in the combustion chamber geometry was applied in order to investigate its effect on the turbulence formation and combustion. The first change consisted in the introduction of a masking wall on the cylinder head, located at the intake side downstream of the valve curtain. The mask showed to be beneficial for the tumble generation during intake, and hence for the turbulence level during combustion. The second change was the modification of the compression ratio, through the modification of the piston shape and the clearance height. This allowed to support the definition of the best CR of the engine, by taking the thermodynamic efficiency, the combustion efficiency as well as the turbomatching quality into account. The second part has been devoted to the high pressure gas injection characterization and mixture formation in a direct injection engine. A moving mesh approach is adopted for the injector meshing to correctly reproduce the injector geometry and the effects of section variation due to the needle lift. The optimization of the grid density distribution and the definition of the numerical schemes and solution algorithm was carried out taking the underexpanded jet gas-dynamics features into account. The model is now ready to be used for the mixing process characterization.

Turbulence Intensity during intake stroke - 450

CAD – CR13 engine @3500 Full load


54 | P a g e

First name: Jiajie LAST NAME: XU

Topic: Analysis of charge motion, injection and mixture formation in a high-performance CNG DI engine

Course year: 1st Tutor(s): Ezio Spessa, Mirko Baratta

Academic context [1] Baratta M. And Rapetto N., “Fluid-dynamic and numerical aspects in the simulation of direct CNG

injection in spark-ignition engines”, Computers and Fluids 103 (2014): 215-233 [2] Baratta M., Catania A.E., and Spessa E., “Multi-dimensional modeling of the direct natural-gas injection

and mixture formation in a stratified-charge SI engine with centrally mounted injector”, SAE World Congress 2008-01-0975


AVL

Centro Ricerca FIAT

Delphi Automotive

Highlights of the research activity The main research activities have been intended to deal with the computational fluid dynamics (CFD) modeling of the charge motion and mixture formation inside a high-performance direct injection (DI) engine fueled by compressed natural gas (CNG). The CFD modeling has been carried out with the commercial code AVL FIRE. Specifically, the major concentration is on the numerical modeling of the CNG injector, as the direct injection is expected to have perceivable influences on the in-cylinder flow fields due to the high-speed gas jet. To improve the accuracy and consistency of the numerical model, the injector is represented as a moving grid that allows the injector needle to move according to a prescribed lift curve throughout the whole injection event. Such moving grid can reproduce the pressure field around the injector nozzle exit, especially during the transient phase of needle opening and closing, which is critical to capture the initial jet development according to previous studies. Due to the large pressure ratio between the upstream and downstream of the injector nozzle (up to 16:1), numerical simulation of the gas jet is challenging. The situation is further complicated by the actual injector geometry as an annular exit where the flow is continuously and variably deflected by the needle and needle seat. After a study on various numerical schemes, solver configurations, and cell size at different regions and along different directions with respect to the nozzle exit, the numerical model under current investigation shows promising results to be able to capture the shock and rarefaction waves.

Gas injection shown by the distribution of fuel concentration

from the SOI (0 deg) to the EOI (30 deg)


55 | P a g e

First name: Yixin LAST NAME: YANG

Topic: Modelling of fuel consumption and emission formation for design and calibration of ICEs in conventional and hybrid powertrains

Course year: 2nd Tutor(s): Prof. Ezio SPESSA, ing. Roberto FINESSO

Academic context [1] Finesso, R., Spessa, E. and Yang, Y., " Development and Validation of a Real-Time Model for the Simulation of the Heat Release Rate, In-Cylinder Pressure and Pollutant Emissions in Diesel Engines," accepted in SAE Int. J. Engines 2016, doi:10.4271/2015-01-9044. [2] Finesso, R., Spessa, E., Venditti, M., and Yang, Y., "Offline and Real-Time Optimization of EGR Rate and Injection Timing in Diesel Engines," SAE Int. J. Engines 8(5):2099-2119, 2015, doi:10.4271/2015-24-2426.


Participation to the research contract between Politecnico di Torino and FPT industrial: F1C PCCI project

Highlights of the research activity - A real-time diesel engine model has been developed. It includes several sub models, namely a predictive heat release model, an in cylinder pressure model, a three-zone thermodynamic model and NOx/soot formation models [ref 1]. This model can be inverted by adopting an iterative procedure, in order to calculate SOI (start of injection of the main pulse) and the injected fuel quantity for given targets of MFB50 (crank angle at which 50% of injected fuel is burned) and BMEP (brake mean effective pressure). - The engine model has been coupled with a conventional vehicle model, and a new methodology has been developed to optimize EGR rate (Xr) and SOI in diesel engines, with the aim of minimizing fuel consumption (FC) and NOx engine-out emissions over different driving missions, including the NEDC, FTP, AUDC, ARDC and AMDC. Different oriented optimizations (FC-oriented, NOx-oriented, FC-NOx oriented) have been investigated [ref 2]. - Moreover, low-throughput semi-empirical models have been developed to estimate the PFP (peak firing pressure), IMEP (indicated mean effective pressure) and BMEP in diesel engines. The BMEP models have also been inverted, in order to calculate the required injected fuel quantity for a given target of BMEP. Thanks to their low throughput feature, the models can be used to develop innovative torque-based control algorithms in the engine control unit. - Finally, the predictive heat release model is currently being used to develop innovative combustion control algorithms to be implemented on a 3.0 L diesel engine, within a research project between POLITO and FPT-Industrial. The project is aimed at implementing PCCI (Premixed Charge Compression Ignition) combustion. The engine is currently installed at the dynamic test bench at Politecnico di Torino. The new control algorithms will be implemented by means of a rapid prototyping device.

Selected values of SOI and Xr (EGR rate)

for the engine operating points over the

AUDC, using the FC-NOx-oriented

optimization

ice

[rpm]

Pic

e [

kW

]

SOI

1500 2500 35000

10

20

30

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50

60-20-18-16-14-12-10-8-6-4-2024

ice

[rpm]

Xr

AUDC --- FC-NOx-oriented ( = 0.75)

1500 2500 3500

00.080.120.160.20.240.280.320.360.40.440.480.52

ice

[rpm]

Pic

e [

kW

]

SOI

1500 2500 35000

10

20

30

40

50

60-20-18-16-14-12-10-8-6-4-2024

ice

[rpm]

Xr


1500 2500 3500

00.080.120.160.20.240.280.320.360.40.440.480.52

ice

[rpm]

Pic

e [

kW

]

SOI

1500 2500 35000

10

20

30

40

50

60-20-18-16-14-12-10-8-6-4-2024

ice

[rpm]

Xr


1500 2500 3500

00.080.120.160.20.240.280.320.360.40.440.480.52


56 | P a g e

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