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Research Article Modeling of Ice Accretion over Aircraft Wings Using a Compressible OpenFOAM Solver Sibo Li 1 and Roberto Paoli 1,2 1 University of Illinois at Chicago, Department of Mechanical and Industrial Engineering, Chicago IL 60607, USA 2 Argonne National Laboratory, Computational Science Division and Leadership Computing Facility, Lemont, IL 60439, USA Correspondence should be addressed to Roberto Paoli; [email protected] Received 20 December 2018; Accepted 15 April 2019; Published 3 June 2019 Guest Editor: Konstantin Volkov Copyright © 2019 Sibo Li and Roberto Paoli. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A method to simulate ice accretion on an aircraft wing using a three-dimensional compressible Navier-Stokes solver, a Eulerian droplet ow eld model, a mesh morphing model, and a thermodynamic model, is presented in this paper. The above models are combined together into one solver and implemented in OpenFOAM. Two-way coupling is achieved between airow eld calculation and ice simulation. The density-based solver rhoEnergyFoam is used to calculate the airow eld. The roughness wall function is proposed to simulate the roughness eect caused by ice accretion. For droplet ow eld calculation, the Eulerian model is applied and the permeable wall boundary condition is used on the wing to simulate the droplet impingement. The icing thermodynamic model is built based on the Messinger model. The mesh morphing model adjusts the wings shape every time step based on the amount of accreted ice so that the airow eld is updated during the simulation. The eect of the ice accretion on the airow is studied by comparing the aerodynamic performancewith and without ice. The ice accretion on the ONERA M6 wing model under a specic condition has been simulated to validate the solvers performance and investigate the eect of the accreted ice on the aerodynamic performance. 1. Introduction Aircraft can experience icing when encountering a cloud that contains supercooled water droplets. It is one of the main hazards to ying due to the degradation of aerodynamic performance because the ice accretion on the wing alters the originally designed aerodynamic conguration. Investi- gation on aircraft icing mechanism and eects is the basis of the anti/deicing technique and the establishment of the ight and operation rules in icing condition. Considerable research has been done, and several approaches have been used to investigate the ice accretion, including the ight test, experimental study, and numerical simulation. Since it is expensive to use the ight test and experimental simulations, numerical simulation is adopted widely. Due to the signicant advances of high performance computing, numerical methods have obtained considerable development. Several codes have been developed to simulate the ice accretion process, and the representative ones are as follows: LEWICE code of NASA [1], TRAJICE code of DRA [2], FENSAP-ICE code [3, 4], the code of ONERA [5], and the code of CIRA [6, 7]. It has been demonstrated that LES modeling produces a more accurate prediction for aerodynamic performance, especially in the study of the near eld of the aircraft wake compared to RANS modeling [8, 9]. However, when applied to turbulent boundary layers, the use of LES is much more computational expensive because of the wall treatment. It is well known that the number of grid points required by LES in the boundary layer exponentially increases with the Reynolds number, which makes LES not feasible on realistic wall-bounded ows. The alternative is to use wall-modeled LES or hybrid RANS-LES. The former imposes a mean velocity prole in the boundary layer whereas the latter couples the RANS equations of calculating the mean ow close to the wall while the LES resolves the turbulence and vortex dynamics far from the wall. In this work, we apply the second method. The Menters K-Omega SST model Hindawi International Journal of Aerospace Engineering Volume 2019, Article ID 4864927, 11 pages https://doi.org/10.1155/2019/4864927
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Page 1: Modeling of Ice Accretion over Aircraft Wings Using a ...downloads.hindawi.com/journals/ijae/2019/4864927.pdfThe governing equations of the rhoEnergyFoam solver are the Navier-Stokes

Research ArticleModeling of Ice Accretion over Aircraft Wings Using aCompressible OpenFOAM Solver

Sibo Li 1 and Roberto Paoli 1,2

1University of Illinois at Chicago, Department of Mechanical and Industrial Engineering, Chicago IL 60607, USA2Argonne National Laboratory, Computational Science Division and Leadership Computing Facility, Lemont, IL 60439, USA

Correspondence should be addressed to Roberto Paoli; [email protected]

Received 20 December 2018; Accepted 15 April 2019; Published 3 June 2019

Guest Editor: Konstantin Volkov

Copyright © 2019 Sibo Li and Roberto Paoli. This is an open access article distributed under the Creative Commons AttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work isproperly cited.

A method to simulate ice accretion on an aircraft wing using a three-dimensional compressible Navier-Stokes solver, a Euleriandroplet flow field model, a mesh morphing model, and a thermodynamic model, is presented in this paper. The above modelsare combined together into one solver and implemented in OpenFOAM. Two-way coupling is achieved between airflow fieldcalculation and ice simulation. The density-based solver rhoEnergyFoam is used to calculate the airflow field. The roughnesswall function is proposed to simulate the roughness effect caused by ice accretion. For droplet flow field calculation, the Eulerianmodel is applied and the permeable wall boundary condition is used on the wing to simulate the droplet impingement. Theicing thermodynamic model is built based on the Messinger model. The mesh morphing model adjusts the wing’s shape everytime step based on the amount of accreted ice so that the airflow field is updated during the simulation. The effect of the iceaccretion on the airflow is studied by comparing the aerodynamic performance—with and without ice. The ice accretion on theONERA M6 wing model under a specific condition has been simulated to validate the solver’s performance and investigate theeffect of the accreted ice on the aerodynamic performance.

1. Introduction

Aircraft can experience icing when encountering a cloud thatcontains supercooled water droplets. It is one of the mainhazards to flying due to the degradation of aerodynamicperformance because the ice accretion on the wing altersthe originally designed aerodynamic configuration. Investi-gation on aircraft icing mechanism and effects is the basisof the anti/deicing technique and the establishment of theflight and operation rules in icing condition.

Considerable research has been done, and severalapproaches have been used to investigate the ice accretion,including the flight test, experimental study, and numericalsimulation. Since it is expensive to use the flight test andexperimental simulations, numerical simulation is adoptedwidely. Due to the significant advances of high performancecomputing, numerical methods have obtained considerabledevelopment. Several codes have been developed to simulatethe ice accretion process, and the representative ones are as

follows: LEWICE code of NASA [1], TRAJICE code ofDRA [2], FENSAP-ICE code [3, 4], the code of ONERA[5], and the code of CIRA [6, 7].

It has been demonstrated that LES modeling produces amore accurate prediction for aerodynamic performance,especially in the study of the near field of the aircraft wakecompared to RANS modeling [8, 9]. However, when appliedto turbulent boundary layers, the use of LES is much morecomputational expensive because of the wall treatment. It iswell known that the number of grid points required by LESin the boundary layer exponentially increases with theReynolds number, which makes LES not feasible on realisticwall-bounded flows. The alternative is to use wall-modeledLES or hybrid RANS-LES. The former imposes a meanvelocity profile in the boundary layer whereas the lattercouples the RANS equations of calculating the mean flowclose to the wall while the LES resolves the turbulence andvortex dynamics far from the wall. In this work, we applythe second method. The Menter’s K-Omega SST model

HindawiInternational Journal of Aerospace EngineeringVolume 2019, Article ID 4864927, 11 pageshttps://doi.org/10.1155/2019/4864927

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[10] is adopted in the current work, and this paper would bean effort to the development of the advanced icing solverbased on hybrid RANS-LES modeling. In this paper, thenumerical simulation consists of four subsolvers: airflowsolver, droplet motion solver, ice thermodynamic solver,and mesh motion solver.

The airflow field is obtained by using a rhoEnergyFoamsolver [11] to solve the compressible Navier-Stokes equa-tions. The rhoEnergyFoam solver is a newly released solverin OpenFOAM open-source community [12], which hasshock-capturing capabilities, and it does not require theburden associated to the calculation of the eigenstates ofNavier-Stokes equations as in characteristics-based schemes,although it maintains the same level of accuracy of theseschemes. The roughness wall function is proposed tosimulate the roughness effect caused by ice accretion.

The Eulerian two-phase model is adopted in the dropletmotion solver coupling with the airflow solver. The droplet-phase governing equations are established by consideringthe droplets in the airflow as a pseudo-fluid and expressedas a continuity equation and a momentum equation. Thedroplet collection efficiency is obtained by solving the gov-erning equations. In addition, the wall boundary conditionshave to be modified to represent the droplet impingementproperly. In the current work, the permeable wall boundarycondition is proposed to mimic the impingement of dropletson the wing.

The thermodynamic model in the ice thermodynamicsolver is based on the classical Messinger model [13]employed by most of the ice accretion solvers. By solvingthe mass balance and energy balance equations, the iceamount generated in every time step is obtained. Then, basedon the assumption that the ice only grows in the normaldirection to the wing’s surface, ice shape is calculated. There-fore, the wing’s shape is changing during the simulationbecause of the ice accretion and airflow field is updatingtogether with it. The droplet collection efficiency is alsorecalculated, and the new ice shape can be built by repeatingthe process.

This paper first presents the four subsolvers used for thesimulation and describes the basic equations. Second, thevalidation of the solver is performed on a two-dimensionalairfoil icing case. Third, the ice accretion on the three-dimensional ONERA M6 wing is simulated to study thesolver’s performance and the results are discussed.

2. Governing Equations of the Two-Phase Flow

2.1. Airflow Solver. For the simulation of unsteady com-pressible flows, the rhoEnergyFoam [11] solver is used.rhoEnergyFoam is a newly released solver in the Open-FOAM open-source community. It is based on AUSM fluxsplitting, which has shock-capturing properties, and it doesnot require the burden associated to the calculation of theeigenstates of Navier-Stokes equations as in characteristics-based schemes, although it maintains the same level of accu-racy of these schemes. In addition, it discretely preserveskinetic energy; indeed, it has been shown to be less dissipativein canonical compressible flow simulations (such as isotropic

turbulence and forward-facing step) and also in aerodynam-ics flow simulations in complex geometries as those targetedin this project.

The governing equations of the rhoEnergyFoam solverare the Navier-Stokes equations for a compressible ideal gas,integrated over an arbitrary control volume V .

ddt V

udV + 〠3

i=1 ∂Vfi − fvi nids = 0, 1

where n is the outward normal and u, fi, and fvi represent theconservative variable vector, the associated Eulerian, andviscous fluxes, respectively. Here, ρ is the density of the air,ui is the velocity component in the i-th coordinate direction,E is the total energy per unit mass, e is the internal energyper unit mass, H is the total enthalpy, σij is the viscousstress tensor, and qi is the heat flux vector.

u =

ρ

ρui

ρE

,

fi =

ρui

ρuiuj + pδij

ρuiH

,

fvi =

0

σij

σikuk − qi

2

Then, the Eulerian fluxes are split into the convective andpressure contribution:

fi = fi + pi =ρui

ρuiuj

ρuiH

+0pδij

03

The convective and pressure fluxes both consist of thecentral part and the diffusive part. The central part of the con-vective flux is evaluated through the midpoint interpolationscheme which discretely preserves kinetic energy of the flowfrom convection, and the pressure flux is evaluated throughthe standard central interpolation. In order to maintain thestability of the simulation, some amount of numerical diffu-sion is necessary. A shock sensor is used in the rhoEnergy-Foam solver to judge the smoothness of the numericalsolution. When capturing shock waves, the artificial diffusionterms provided by the AUSM [14] scheme are applied to pres-sure and convective fluxes.

The RANS (Reynolds-Averaged Navier-Stokes) modelsusually underpredict the convective heat flux because theyconsider the wall as smooth while the icing surfaces are quite

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rough. Therefore, the thermal wall function derived byLima da Silva et al. [15] has been implemented to studythe roughness effect, in which the roughness effect is con-sidered by using the momentum and heat transfer analogyfactor. Here, αt is the turbulent thermal diffusivity.

αt =μtPrt

⋅ 2 ⋅ η,

η = 1Prt + Cf /2/ C ⋅ Ks

+a ⋅ Prb,

Ks+ = UτKs

v,

4

where μt is the turbulent viscosity, Prt is the turbulentPrandtl number, Cf is the rough skin friction, Uτ is theshear velocity, and Ks is the equivalent sand-grain rough-ness. a, b, and C are defined by Stefanini et al. [16] asthree constants as -0.45, -0.8, and 1.42, respectively.

2.2. Droplet Motion Solver. The governing equations forthe droplet phase are established based on the followingassumptions:

(1) The distribution of the water droplets is uniform, andthey are simplified as sphere with a median volumet-ric diameter

(2) The physical parameters of the droplets does notchange by assuming that there is no heat or masstransfer between the droplets and air

(3) The droplet collision, splashing, and bouncing effectsare neglected

(4) The airflow viscosity has no effect on the droplets

∂αρw∂t

+∇ ⋅ αρwuw = 0,

∂αρwuw∂t

+∇ ⋅ αρwuwuw = αρwg + F,5

where α represents the droplet volume fraction andρw and uw are the droplet density and velocity,respectively. In the momentum equation, g is the

gravity factor and F is the drag force caused byairflow, which can be calculated as follows:

F = αρwf Rerτp

u − uw , 6

where Rer is the Reynolds number, τp = ρwd2p/18µ,

and dp is the droplet diameter. f Rer can becalculated by

f Rer = 1 + 0 15 Re0 687r + 0 0175 Rer

1 + 45000 Re−1 16r

7

The Gauss’s theorem is firstly applied to convert thespatial integral to surface integral. Then, the first-orderupwind scheme is used for divergence terms, and the timeintegration of the resulting ordinary differential equationssystem is carried out by a third-order, four-stage Runge-Kutta algorithm.

y l = y 0 + αldtL y l−1 , 8

where y represents the conservative variables αρw andαρwuw, dt is the time step size, and L y is the spatialderivative.

Based on the previous assumption that the dropletsplashing and bouncing effects are neglected, the dropletswould adhere to the wall after impingement, which meansthat the high velocity of droplets comes to zero instanta-neously upon impingement. However, since the viscosity isnot considered in the droplet phase, the no-slip wall bound-ary condition applied in the airflow field cannot be used inthe droplet phase. On the other hand, the droplet volumefraction cannot be set as zero on the wall because it willprevent the occurrence of any impingement. Therefore, aspecific wall boundary condition is applied on the wing tosatisfy the mass conservation while at the same time it allowsfor droplet impingement. For simplicity, it is illustrated inFigure 1 in which the droplet velocity component normalto the wall is represented by vwn. Upon the impingement,the zero-gradient boundary condition is applied for bothdroplet velocity and droplet volume fraction. Otherwise, ifthe droplet splashing is detected, the fixed value boundary

Wing

Impingement

C vwc, �훼c

vwb = vwc, �훼b = �훼c

vwb, �훼bB

(a)

vwc, �훼c

vwb = 0, �훼b = �훼min

vwb, �훼bWing

No impingement

C

B

(b)

Figure 1: Permeable wall boundary conditions. (a) Impingement. (b) No impingement.

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condition is applied so the droplet volume fraction isassigned with a minimal value and the droplet velocity isset to be zero to prevent it from splashing on the wall. Inorder to differentiate between the impingement area andthe non-impingement area, in the control volumes adjacentto the wall, we check the direction of the droplet velocitycomponent in the normal direction of the wall. This isillustrated in Figure 2: when vwn > 0, no impingementoccurs while when vwn < 0, droplet impingement on thewall is expected.

The droplet volume fraction and droplet velocityare obtained by solving the governing equations. Then,the nondimensional local collection efficiency β is cal-culated by

β = −αnuw ⋅ nuw∞

, 9

where αn is α/α∞, represents the normalized dropletvolume fraction, n represents the normal direction,and uw∞ is the droplet velocity in the free stream.

3. Thermodynamic Modeling

Different icing conditions cause different types of iceaccretion. Rime ice accretion occurs when supercooled waterdroplets freeze instantaneously upon impact on the aircraftwings. If the environmental temperature is not low enough,the droplets may runback as liquid water to form glaze ice.The current thermodynamic model is based on the Mes-singer model [13] which was employed by a few commercialicing codes such as LEWICE [1], TRAJICE [2], and ONERA[5]. However, these icing codes assume that the freezingfraction stays constant during the icing simulation, which isnot accurate. More recently, Cao et al. [17, 18] include thefreezing fraction as a changing variable in the icing simula-tion. In this paper, the freezing fraction is updating through-out the simulation and the ice height is obtained by solvingthe mass balance equation and energy balance equation.

3.1. Mass Balance. As shown in Figure 3, in the controlvolume on the wing’s surface, the mass balance equationcan be written as follows:

mimp +mflow in =mice +mflow out +mes, 10

where mimp represents the mass flux of water impacting thewing’s surface, mice is the mass flux of generated ice, mesrepresents the mass flux of evaporation or sublimation, andmflow in and mflow out denote the mass flux of water flow intothe control volume and flow out of the control volume,respectively.

mimp = LWC ⋅ β ⋅ uw∞, 11

mice = f ⋅ mimp +mflow in −mes , 12

mflow out = 1 − f ⋅ mimp +mflow in −mes , 13

where LWC is the liquid water content and f is thefreezing fraction.

f = micemimp +mflow in −mes

14

3.2. Energy Balance. Figure 4 shows the energy balanceequation which is necessary to obtain the balance tempera-ture and the freezing fraction. Its establishment and solutionare based on the following assumptions:

(1) There is no runback water in the control volume atthe stagnation point, and any runback water flowingout of the control volume flows along the directionaway from the stagnation point

(2) The heat and mass transfer only happens in thedirection normal to the wing’s surface

(3) In the mixture of water and ice, a balance tempera-ture is reached

Then, the energy balance equation can be written asfollows:

Qca +Qimp +Qlatent +Qsensible = 0, 15

where the four energy terms represent the convectiveheat, impingement heat, latent heat, and sensible heat,respectively. The descriptions of these energy terms aregiven below.

Wing

Volume centervwn (+)

vwn (−)

Figure 2: A control volume adjacent to the wall.

WingIce

mflow out·

mes·mimp

·

mflow in·

Figure 3: Mass balance in the control volume.

Wing

Ice

Qca·

Qsensible·Q

simp·

Qlatent·

Figure 4: Energy balance in the control volume.

4 International Journal of Aerospace Engineering

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The convective heat can be calculated as

Qca = hc Trec − Tb , 16

where Tb and Trec represent the balance temperature andrecovery temperature in the control volume and hc is theconvective heat transfer coefficient.

The impingement heat can be calculated as

Qimp =12mimpu

2imp, 17

where mimp is the water impingement mass flux and uimp isthe water droplet impinging velocity. Both of them areobtained from the droplet solver solutions.

The latent heat can be calculated as the sum of latent heatof freezing and latent heat of sublimation or evaporation.

Qimp =Qfreeze +Qes,

Qfreeze = Lf ⋅ f ⋅ mimp +mflow in ,

Qes = −Les ⋅mes,

18

where Lf and Les represent the latent heat of freezing and thelatent heat of sublimation or evaporation, respectively.

The sensible heat consists of all the heat exchanged bywater without changing state. Firstly, the temperature of theimpinging water is increased to freezing temperature T f atwhich the state change happens. Then, in the control volume,the newly formed ice and the liquid water reach the balancetemperature Tb.

Qsensible =Qsimp +Qsflow in +Qsice +Qsflow out,

Qsimp =mimp ⋅ Cpw ⋅ T imp − T f ,

Qsflow in =mflow in ⋅ Cpw ⋅ T flow in − T f ,

Qsice =mice ⋅ Cpi · T f − Tb ,

Qsflow out =mflow out ⋅ Cpw ⋅ T f − Tb ,

19

where Cpw and Cpi represent the specific heat of waterand ice, respectively. T imp and T flow in represent the tem-perature of the impinging water droplets and the temper-ature of runback water from the previous control volume,respectively.

3.3. Solution of the Mass and Energy Balance Equations. Bycombining equation (15) with equation (13), an equationwith unknown variables f and Tb can be obtained. The valueof f must be between 0 and 1 due to the icing physicalprocess, which provides a constraint for this equation. Thesolving procedure is a predictor-corrector methods which

starts from the stagnation point and along the upper andlower surfaces of the wing. Firstly, it is assumed that boththe water and ice exist in the control volume and the balance

Figure 5: Mesh of the NACA0012 airfoil.

−0.06

−0.04 0.00 0.04 0.08x/c

AirfoilNumerical data (Cao et al., 2012)Experiment data (Shin & Bond, 1992)Current study

0.12 0.16

−0.04

−0.02

0.00y/c

0.02

0.04

0.06

0.08

Figure 6: Ice shape comparison on NACA0012 airfoil.

Figure 7: Mesh distribution on the ONERA M6 wing.

5International Journal of Aerospace Engineering

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temperature Tb is reached. Then, the freezing fraction f canbe calculated, which have three possible scenarios:

(1) 0 < f < 1: the assumption is correct. Both water andice exist in the control volume and the calculationwill be continued to the next control volume basedon this f

(2) f ≥ 1: there is no water in the control volume and thevalue of f will be assigned with 1 to continue thecalculation

(3) f ≤ 0: there is no ice accretion

3.4. Ice Shape Reconstruction. Based on the assumptionthat the ice grows only in the normal direction to thewing’s surface, the ice height during time step ΔT canbe written as

hice =miceΔT

ρi, 20

where ρi is the density of the ice.

The irregular ice shape represents a major challenge innumerical simulation of long-time icing. Because the iceaccretion changes the wing’s shape, the previously solvedairflow field and droplet flow field are also influenced.Therefore, it is necessary to recalculate the airflow fieldand droplet flow field in order to obtain the new ice shapeaccurately based on the updated mesh. However, manualremeshing is a time-consuming procedure. In the currentwork, a mesh movement scheme is presented.

At each time step, the mesh nodes next to the wing movein the normal direction to the wing’s surface with thedistance calculated from equation (20). Therefore, the iceshape is constructed by the first layer nodes. The movementof the rest of the mesh nodes is decided by solving the Laplaceequation with variable diffusivity.

∇ ⋅ γ∇dm = 0, 21

where γ is the diffusivity and dm is the node motion displace-ment. The diffusivity field is calculated based quadraticallyon the inverse of the cell center distance to the nearestboundary which is a wing in this case. Therefore, the nodes

0.10.0e + 00 0.2 0.3 0.4 0.5 0.5e - 01Beta

Figure 8: Visualization of the collection efficiency on the wing.

0.005 0.002 0.003 0.004 Ice height

0.0e+00 5.9e-030.001

Figure 9: Visualization of the ice height distribution on the wing.

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which are far from the wing have smaller motion displace-ment than the ones which are close to the wing.

4. Results and Discussions

In this section, the developed solver is tested against varioustwo- and three-dimensional cases. Firstly, icing simulationis performed on two-dimensional NACA0012 airfoil for

validation. Then, the ice accretion on three-dimensionalONERA M6 wing and the influence of the ice accretion onthe airflow field are investigated.

4.1. Ice Accretion on NACA0012 Airfoil. Figure 5 shows thecomputational mesh for NACA0012 airfoil, which contains6200 cells. The chord of the airfoil is c = 0 53m, and thecomputational far field domain extends to 50c. The angle of

−0.04

0.5

PredictedClean

0.6x

0.7

0.00y

0.04

A. 90% Semispan

(a) Section A

−0.04

0.30 0.35 0.40 0.45x

0.50

0.00y

0.04

PredictedClean

A. 90% Semispan

(b) Section B

−0.04

0.1 0.2x

0.3

0.00y

0.04

PredictedClean

A. 90% Semispan

(c) Section C

Figure 10: Predicted ice shape at three ONERA M6 wing sections.

7International Journal of Aerospace Engineering

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attack is 4°, the free stream velocity is u∞ = 67 05m/s,and the pressure is p∞ = 101300 Pa. The static temperatureT = 244 7K. For the droplet phase, LWC = 1 0 g/m3 and themedian volumetric diameter (MVD) is 20μm. The icing timeis 360 seconds.

Figure 6 shows the ice shape comparison between thepredicted results in this paper, experimental data [19], andpredicted results from Cao et al. [17]. The typical rime iceaccretion happens in this case due to the relatively lowenvironmental temperature. From the comparison plot, agood agreement is obtained.

4.2. Ice Accretion on ONERAM6Wing. The mesh of ONERAswept M6 is shown in Figure 7 and contains 671160 cells.The mean aerodynamic chord is c = 0 53m, the semispanis b = 1m, and the computational domain extends to 20c.The angle of attack is 6°, the free stream Mach numberis Ma∞ = 0 15, the static temperature T = 265K, and theReynolds number is Re = 2 17 × 10 [6]. For the droplet

0.0−1.0

−0.5

0.0

0.5

1.0

1.5

2.0

2.5

0.2

lced wingClean wing

−Cp

0.4 0.6(x-xl)/(xt-xl)

0.8 1.0

(a) Section A

−1.0

−0.5

0.0

0.5

1.0

1.5

2.0

−Cp

0.0 0.2 0.4 0.6 0.8 1.0(x-x

l)/(x

t-x

l)

lced wingClean wing

(b) Section B

0.0 0.2 0.4 0.6 0.8 1.0−1.0

−0.5

0.0

0.5

1.0

1.5

2.0

−Cp

(x-xl)/(x

t-x

l)

lced wingClean wing

(c) Section C

Figure 11: Pressure coefficient at three ONERA M6 wing sections.

0

0.0 0.1 0.2 0.3

Clean wingIced wing

x/c

0.4 0.5

200

4000

6000

8000

Peak

vor

ticity

mag

nitu

de

10000

12000

14000

16000

Figure 12: Peak vorticity magnitude along free stream direction.

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0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1

–0.3

–0.2

–0.1

0

0.1

0.2

0.3

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1

–0.3

–0.2

–0.1

0

0.1

0.2

0.3

Vorticity magnitude1000 2000 3000 40000.0e + 00 5.0e + 03

0

Z (m

)

Z (m

)

Z (m

)

Z (m

)Z

(m)

Z (m

)

Y (m)

Y (m)

Y (m)

Y (m)

0

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1

–0.3

–0.2

–0.1

0

0.1

0.2

0.3

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)

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Figure 13: Cross-sectional distributions of vorticity magnitude at different downstream locations for the clean (a) and iced (b) wing. Fromtop to bottom: x/c = 0, x/c = 0 22, and x/c = 0 5.

9International Journal of Aerospace Engineering

Page 10: Modeling of Ice Accretion over Aircraft Wings Using a ...downloads.hindawi.com/journals/ijae/2019/4864927.pdfThe governing equations of the rhoEnergyFoam solver are the Navier-Stokes

phase, LWC = 1 0 g/m3 and MVD= 20 μm. The icing timeis 200 seconds.

The calculated collection efficiency is presented inFigure 8 which shows that its value is higher in the lowerregion of the wing. Since the wing is at 6° angles of attack,the main impingement region is the lower surface of thewing. The same phenomenon is also observed in the iceheight distribution presented in Figure 9. The predicted iceshape at three sections: section A 90% span, section B 60%span, and section C 20% span, is shown in Figures 10(a)–10(c). It can be seen that the thickness of the ice accretionincreases from the root to the tip of the wing which agreeswith the distribution of the local collection efficiency.

In order to study the impact of ice accretion on theaerodynamic performance of the wing, we compare the com-puted distributions of pressure coefficient with and withoutice, which are shown in Figures 11(a)–11(c). xl and xt denotethe coordinates of the leading edge and trailing edge of eachwing section, respectively. In the three sections, the ice accre-tion’s influence on pressure coefficient at section A is themost significant one because the ice thickness increases fromthe root to the tip. And the irregular ice shape severelychanged the pressure coefficient distribution.

Also, in order to study and understand the impact of iceaccretion on the tip vortex, Figure 12 shows the comparisonof peak vorticity magnitude along the free stream directionwith and without ice. Ice accretion on the wing reduced thestrength of the vortex close to the wing tip. It also causedsome disturbance to the peak vorticity along the free streamdirection due to the irregular shape of the ice accreted onthe wing. The peak vorticity keep decreasing as it moves awayfrom the wing tip when ice formation is not considered.However, icing produces local overshoots as the nonuniformgrowth on the wing surface. These oscillations eventuallysmooth out at sufficiently large distance from the trailingedge. The same phenomenon is also observed when com-paring vorticity magnitude distribution with and withoutice at the three sections after the wing tip: x/c = 0, 0.22,and 0.5 as shown in Figure 13. It can be seen that thevorticity distribution for the iced wing is much more irreg-ular and the vortex with medium strength is more widelyspread. This could have potential impact on the safetyspace between aircraft at takeoff and landing [20] becauseit has been shown in this study that the ice accretion onthe wing will affect the aircraft wakes.

5. Conclusions

A three-dimensional model is established to predict the iceaccretion on the wing as well as the ice’s impact on the aero-dynamic performance of the wing. The ice accretion has beensimulated on a 2-D NACA0012 airfoil and a 3-D ONERAM6 wing. All the results show that this solver is feasible.

The model solves the icing problem by a two-waycoupled procedure. The airflow field is solved by usingdensity-based solver rhoEnergyFoam with the AUSM fluxsplitting scheme. The droplet motion field is solved explicitlyin an Eulerian field with Runge-Kutta time-advancingscheme. The specific impinging boundary condition and

the roughness wall function effectively help with simulatingthe icing phenomenon. The remeshing model based on aLaplace equation functions well to capture the ice shapeand prepare for the study of the updated airflow field.

The study on the impact of ice accretion on the aerody-namic performance of the wing shows that the pressurecoefficient near the tip of the wing is greatly affected by theice. Also, it is noted that the ice accretion has importanteffects on both the tip vorticity distribution and the peak vor-ticity along the free stream direction. This work represents afirst step of a larger project that is aimed at developing ahybrid RANS-LES solver to simulate icing over aerodynamicsurfaces. Next steps will be, first, to test detached-eddysimulations based on (1) or (2) equation turbulence modelsand then to couple the ice formation/growth model intothose solvers.

Data Availability

The data used to support the findings of this study areavailable from the corresponding author upon request.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

Acknowledgments

Computer time was provided by ACCC at UIC on theuniversity cluster “Extreme.” This work was supported byArgonne National Laboratory through grant #ANL 4J-30361-0030A “Multiscale Modeling of Complex Flows.”

References

[1] G. Ruff and B. Berkowitz, “User’s manual for the NASALewis ice accretion prediction code (LEWICE),” Tech. Rep.NASA-CR-185129, NASA, 1990.

[2] R. Gent, “TRAJICE2 – a combined water droplet trajectoryand ice accretion prediction program for aerofoils,” Tech.Rep. RAE TR90054, Royal Aircraft Establishment, 1990.

[3] H. Beaugendre, F. Morency, and W. G. Habashi, “FENSAP-ICE’s three-dimensional inflight ice accretion module:ICE3D,” Journal of Aircraft, vol. 40, no. 2, pp. 239–247, 2003.

[4] H. Beaugendre, F. Morency, W. G. Habashi, and P. Benquet,“Roughness Implementation in FENSAP-ICE: Model Calibra-tion and Influence on Ice Shapes,” Journal of Aircraft, , no. 6,pp. 1212–1215, 2003.

[5] T. Hedde and D. Guffond, “ONERA three-dimensional icingmodel,” AIAA Journal, vol. 33, no. 6, pp. 1038–1045, 1995.

[6] G. Mingione and V. Brandi, “Ice accretion prediction onmulti-element airfoils,” Journal of Aircraft, vol. 35, no. 2,pp. 240–246, 1998.

[7] P. Louchez, G. Fortin, G. Mingione, and V. Brandi, “Beads andrivulets modeling in ice accretion on a wing,” in 36th AIAAAerospace Sciences Meeting and Exhibit, Reno, NV, USA, 1998.

[8] R. Paoli and H. Moet, “Temporal large-eddy simulations ofthe near-field of an aircraft wake,” Open Journal of FluidDynamics, vol. 8, no. 2, pp. 161–180, 2018.

10 International Journal of Aerospace Engineering

Page 11: Modeling of Ice Accretion over Aircraft Wings Using a ...downloads.hindawi.com/journals/ijae/2019/4864927.pdfThe governing equations of the rhoEnergyFoam solver are the Navier-Stokes

[9] D. Kolomenskiy and R. Paoli, “Numerical simulation of thewake of an airliner,” Journal of Aircraft, vol. 55, no. 4,pp. 1689–1699, 2018.

[10] F. R. Menter, “Two-equation eddy-viscosity turbulencemodels for engineering applications,” AIAA Journal, vol. 32,no. 8, pp. 1598–1605, 1994.

[11] D. Modesti and S. Pirozzoli, “A low-dissipative solver forturbulent compressible flows on unstructured meshes, withOpenFOAM implementation,” Computers & Fluids, vol. 152,no. 14, pp. 14–23, 2017.

[12] H. G. Weller, G. Tabor, H. Jasak, and C. Fureby, “A tensorialapproach to computational continuum mechanics usingobject-oriented techniques,” Computers in Physics, vol. 12,no. 6, pp. 620–631, 1998.

[13] B. L. Messinger, “Equilibrium temperature of an unheatedicing surface as a function of air speed,” Journal of the Aero-nautical Sciences, vol. 20, no. 1, pp. 29–42, 1953.

[14] M. S. Liou and C. J. Steffen Jr., “A new flux splitting scheme,”Journal of Computational Physics, vol. 107, no. 1, pp. 23–39,1993.

[15] G. Lima da Silva, M. Arima, N. Branco, and M. Pimenta,“Proposed wall function models for heat transfer around acylinder with rough surface in cross flow,” in SAE 2011 Inter-national Conference on Aircraft and Engine Icing and GroundDeicing, Chicago, IL, USA, 2011.

[16] L. M. Stefanini, O. M. Silvares, A. L. Silva, and E. J. G. Jesus,“Heat Transfer on Iced Cylinders,” in AIAA Atmospheric andSpace Environments Conference, Toronto, Ontario, Canada,2010.

[17] Y. Cao, C. Ma, Q. Zhang, and J. Sheridan, “Numerical simula-tion of ice accretions on an aircraft wing,” Aerospace Scienceand Technology, vol. 23, no. 1, pp. 296–304, 2012.

[18] Y. Cao, J. Huang, and J. Yin, “Numerical simulation of three-dimensional ice accretion on an aircraft wing,” InternationalJournal of Heat and Mass Transfer, vol. 92, no. 34, pp. 34–54,2016.

[19] J. W. Shin and T. H. Bond, Experimental and computationalice shapes and resulting drag increase for a NACA 0012 airfoil,NASA Technical Memorandum 105743, 1992.

[20] F. Holzäpfel, M. Frech, T. Gerz et al., “Aircraft wake vortexscenarios simulation package – WakeScene,” AerospaceScience and Technology, vol. 13, no. 1, pp. 1–11, 2009.

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