Proposal to establish a laboratory for combustion studies
Jayr de Amorim Filho Brazilian Bioethanol Science and Technology Laboratory
SCRE – Single Cylinder Research Engine Laboratory
OUTLINE Requirements, Project Goals and Solutions Proposals Research tasks and technologies Single Cylinder Test bed and Engines Research tools for combustion studies with SCREs
Project Goals and Suggested Solutions
PROJECT GOALS
1. Development of Spark Plugs – project design ; effects on ignition, plasma and flame development
2. Investigation of deposits on spark plug and in the engine
3. Emission studies; e.g. NO, OH, HC, CH.
4. Cold start investigations
5. Direct injection spray and evaporation investigations (Injector Development)
Test bed system: SCE, SCTB and peripherals
infrastructure:
mechanical, media,
energy, environment
SCE:
Air: NA
Fuel: Ethanol - Gasoline
ECU: open engine controller
SCTB:
compact test bed with active dyno, test bed controller
Engine conditioning:
external coolant / lube oil supply at regulated temperature and pressure
SCE SCTB shaft
controller SCE
controller SCTB
data data
analyser analyser
interpretation
Optical Instrumen -
tation
analyser
data
controller
Optical access SCE SCTB shaft
controller SCE
controller SCTB
data data
analyser analyser
interpretation
Diagnostic Instrumen -
tation
analyser
data
controller
Optical access
Access to infrastructure:
concrete base floor, cooling water, electric power supply, air in, exhaust out
Peripherals, Diagnostics: to be defined to meet the needs
Project Application Matrix
SCRE – Single Cylinder Research Engine
Considerations for choosing the right components
1. What is the application target?
2. What engine configuration is required for this application? (fuel, injection and combustion
type, naturally aspirated or charged, size, thermodynamic or optical engine)
3. What instrumentation and measurement devices are required for the desired application?
(Imaging, thermodynamics, LIF, gas analysis etc.)
4. What test cell equipment is required for safe operation and measurement?
(conditioning units, fuel measurement, blow by, air mass flow, temperatures and pressures…)
5. What special measurement systems are planned to be used, and what integration is
required? (LIF, combustion analysis, emission…)
6. What are the requirements for the test cell and installation?
7. What trainings are required to operate the equipment safely and achieve the desired
results ?
SCRE – Single Cylinder Research Engine
OUTLINE Requirements, Project Goals and Solutions Proposals Research tasks and technologies to achieve them Introduction to Single Cylinder Test bed and Engines Research tools for combustion studies with SCREs
Spark Plug Development
Goals Investigation of ignition behavior, temperatures and deposits Spark Plug Development Recommended Solutions Development of the spark plug requires operation under realistic conditions including high load and long term operation. For the investigations an optical access through endoscope with high resolution camera for flame investigation or infrared camera for surface temperature investigations can be used.
Schematic of experimental setup
Electrical Parameters for Duty Cycle of 25 %.
10 15 20 25 30 35 40
5500
6000
6500
7000
Pea
k V
olta
ge
(V
)
Duty Cycle (%)
10 15 20 25 30 35 402,2
2,4
2,6
2,8
3,0
3,2
3,4
3,6
3,8
Pe
ak C
urr
en
t (m
A)
Duty Cycle (%)
Results
Spark Plug Discharge Electrical Characterization
Discharge temperature characterization • The gas temperature was estimated from the rotational spectrum of the SPS of N2 (C3Πu → B 3Πg ) using a comparison between the experimental spectra and the simulated ones.
3310 3320 3330 3340 3350 3360 3370 3380 33900,0
0,2
0,4
0,6
0,8
1,0
Inte
nsity (
a.u
.)
Wavelength (A)
Experimental
Simulated
Trot
=(2058 ± 75) K
Electron density characterization • Determined by Stark broadening on Hα emission line.
654,5 655,0 655,5 656,0 656,5 657,0 657,5 658,0
-20
0
20
40
60
80
100
120
140
160
180
Inte
nsity (
a.u
.)
H, Duty Cycle 40%
Ajuste Voigt
Wavelength (nm)
][10646,011 nmneStark
][119 nmT
PX
g
hressonante
][45,37,0
__ nmPTgWaalsdervan
][1002,2 4 nmNatural
][107,4 4 nmT hDoppler
Broadening Mechanisms
0 1 2 3 4 5 6
4,0x1014
6,0x1014
8,0x1014
1,0x1015
1,2x1015
1,4x1015
1,6x1015
1,8x1015
Ele
ctr
on
de
nsity (
cm
-3)
Time (ms)
ne_D10%
ne_D15%
ne_D20%
ne_D40%
Electron temperature characterization • Determined by Saha equation using Argon emission lines.
748,6 750,5 752,4 754,3
0
200
400
600
800
1000
1200
473,1 475,0 476,9 478,8
0
20
40
60
80
0 1 2 3 4 5 6
17000
17500
18000
18500
19000
19500
20000
20500
Ele
ctr
on
te
mp
era
ture
(K
)
Time(ms)
Te D10%
Te D15%
Te D20%
Te D40%
Thermal imaging + calibration
In-cylinder temperature evaluation
Technical details: Fused silica window,
endoscope with BK7 imaging optics,
B/W camera, 10 ms exposure time in
exhaust / intake stroke.
Direct view onto spark plug.
Endoscope access from pent roof
side
Objects: Spark plug or exhaust valves
Thermal imaging – local sensitivity
Thermocouple on sparkplug: radiation to temperature calibration
500
600
700
800
900
0 1000 2000 3000 4000
Radiation intensity [rel. unit]
Tem
p. [
deg
C]
Window, endoscope and
camera local sensitivity, use
camera calibration device
Thermal image
Radiation to temperature
conversion, use temperature
calibration device
Thermal image……. x local sensitivity field x calibration curve ………yields temperature
field
Temperature field On engine test
bed
18
In-cylinder thermal imaging: example on ignition timing effects
Flame and Plasma Spectroscopy & Imaging
Goals
Analysis of Flame and Plasma properties under real combustion conditions
Recommended Solutions
Flame and Plasma investigations require the best possible access to the spark plug and combustion chamber, and stable conditions for best repeatability and comparability. Therefore the recommended engine is a transparent SCRE with pent roof glass liner (full access to spark plug), piston with glass window and mirror unit (optical access from below) and port fuel injection (MPFI) for stable, homogeneous air-fuel mixture.
Transparent Engine: Example Flame Imaging
Studies of interaction between injection, mixture
formation and combustion with different optical
technologies.
High speed or high-resolution imaging through
glass cylinder liner or piston window, mostly for
studies of wall wetting and dispersed droplets leading
to local sooting combustion.
PLIF studies for investigation of non-reacting as
well as reacting gas and liquid flows in a nonintrusive,
instantaneous flow visualization with high spatial and
temporal resolution.
Ethanol DI Cold Start Investigation
Spray and Injector Analysis
Goals
Analysis and optimization of injection strategies for starting engines with Ethanol at low
temperatures
Recommended Solutions
The critical point of engine starting in low temperature, especially with Ethanol is the
evaporation of the fuel. To find the best timing and strategies for the injection, a SCRE
with glass liner and high pressure direct injection system is required.
Using imaging with high speed cameras, the injection spray and the resulting flame
can be filmed. Since liquid fuel is burning with a much brighter flame, this technique
clearly shows wall wetting and liquid fuel droplets, and can be used to analyse influences
of injection parameters like timing, pressure or injector type on the starting process.
Transparent Engine: Example Spray Imaging
Spray studies to investigate influences of injection timing, injection pressure and injection hardware. Using imaging technologies allows fuel droplet analysis. Using Laser Induced Fluorescense (LIF) allows fuel vapor distribution studies. The active dyno of the SCTB allows motoring the SCRE to conduct spray and vapor formation studies without combustion.
Fuel pressure 4 bar Fuel pressure 40 bar
Big droplets Small droplets
Wall film Significantly reduced wall film
SCRE – Single Cylinder Research Engine Laboratory
OUTLINE Requirements, Project Goals and Solutions Proposals Research tasks and technologies Single Cylinder Test bed and Engines Research tools for combustion studies with SCREs
Single Cylinder Compact Test Bed
Specifications for single cylinder research engines test bed: Completely assembled with engine, active dyno, dyno control and conditioning systems for Engine Very low requirements for facility: - no special foundations or baseplates - only electrical and water supply needed The SCTB can be easily moved with a fork lift Flexible use with different engines , also multi cylinder up to 60kW/200Nm
Single Cylinder Engine and Test Bed Installation and key features
• Modular concept to combine the reliability of standard components with flexibility for specific solutions. • Very low requirements for installation.
Transparent Research Engine with port fuel and direct injection systems
SCRE with pent-roof glass liner and mirror system that allows optical access with cameras and other optical systems like Spectrometry systems or LIF: Flame and spray studies with high resolution or high speed cameras. Studies of injection parameter variation and optimization for reduced wall wetting and optimized mixture formation and combustion. Allows detailed studies of mixture formation and combustion with spectrometry, LIF or other techniques with full optical access to combustion chamber due to the pent-roof glass liner and piston window
Thermodynamic Research Engine with port fuel and direct injection systems
SCRE spark ignited engine for combustion development and research also under high-load, high-speed and long-term operation. Combustion analysis by means of pressured based measurement (indicating) or endoscopic optical access to the combustion chamber. Surface temperature investigations on spark plug and valves with endoscope and infrared camera. High load and simulated turbo-charged operation. Emission trend analysis with FTIR and Online Soot Measurement. Long term operation possible for study of deposits and corrosion.
SCRE – Single Cylinder Research Engine Laboratory
OUTLINE Requirements, Project Goals and Solutions Proposals Research tasks and technologies to achieve them Introduction to Single Cylinder Test bed and Engines Research tools for combustion studies with SCREs
SESAM-FTIR R&D Emission Analyzer with Infrared Spectroscopy
Thermodynamic analysis of combustion: Indicating System and GCA Gas Exchange and Combustion Analysis
Fuel Consumption Measurement Fuel Measurement Systems and Sensors for SCRE
Conclusion
Project management techniques required to build a modern test facility are the same as those for any multidisciplinary laboratory construction. New diagnostics need to be developed for contaminants detection in ethanol. Discharge phase parameters may be characterized using passive and active spectrocopies. Better understanding of combustion and pollutant formation processes in IC engines.