Turbulence Modeling Effects on the CFD Predictions of Flow over a Detailed Full-Scale Sedan Vehicle
In today’s road vehicle design processes, Computational Fluid Dynamics (CFD) has emerged as one of the major investigative tools for aerodynamics analyses. The age-old CFD methodology based on the Reynolds Averaged Navier−Stokes (RANS) approach is still considered as the most pop...
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doaj-5dcba9dc38a045d59c4d7aa939e917962020-11-25T00:50:12ZengMDPI AGFluids2311-55212019-08-014314810.3390/fluids4030148fluids4030148Turbulence Modeling Effects on the CFD Predictions of Flow over a Detailed Full-Scale Sedan VehicleChunhui Zhang0Charles Patrick Bounds1Lee Foster2Mesbah Uddin3North Carolina Motorsports and Automotive Research Center, UNC Charlotte, 9201 University City Blvd, Charlotte, NC 28223, USANorth Carolina Motorsports and Automotive Research Center, UNC Charlotte, 9201 University City Blvd, Charlotte, NC 28223, USAHyundai America Technical Center, Inc., 6800 Geddes Road, Superior Township, MI 48198, USANorth Carolina Motorsports and Automotive Research Center, UNC Charlotte, 9201 University City Blvd, Charlotte, NC 28223, USAIn today’s road vehicle design processes, Computational Fluid Dynamics (CFD) has emerged as one of the major investigative tools for aerodynamics analyses. The age-old CFD methodology based on the Reynolds Averaged Navier−Stokes (RANS) approach is still considered as the most popular turbulence modeling approach in automotive industries due to its acceptable accuracy and affordable computational cost for predicting flows involving complex geometries. This popular use of RANS still persists in spite of the well-known fact that, for automotive flows, RANS turbulence models often fail to characterize the associated flow-field properly. It is even true that more often, the RANS approach fails to predict correct integral aerodynamic quantities like lift, drag, or moment coefficients, and as such, they are used to assess the relative magnitude and direction of a trend. Moreover, even for such purposes, notable disagreements generally exist between results predicted by different RANS models. Thanks to fast advances in computer technology, increasing popularity has been seen in the use of the hybrid Detached Eddy Simulation (DES), which blends the RANS approach with Large Eddy Simulation (LES). The DES methodology demonstrated a high potential of being more accurate and informative than the RANS approaches. Whilst evaluations of RANS and DES models on various applications are abundant in the literature, such evaluations on full-car models are relatively fewer. In this study, four RANS models that are widely used in engineering applications, i.e., the realizable <inline-formula> <math display="inline"> <semantics> <mrow> <mi>k</mi> <mo>−</mo> <mi>ε</mi> </mrow> </semantics> </math> </inline-formula> two-layer, Abe−Kondoh−Nagano (AKN) <inline-formula> <math display="inline"> <semantics> <mrow> <mi>k</mi> <mo>−</mo> <mi>ε</mi> </mrow> </semantics> </math> </inline-formula> low-Reynolds, SST <inline-formula> <math display="inline"> <semantics> <mrow> <mi>k</mi> <mo>−</mo> <mi>ω</mi> </mrow> </semantics> </math> </inline-formula>, and V2F are evaluated on a full-scale passenger vehicle with two different front-end configurations. In addition, both cases are run with two DES models to assess the differences between the flow predictions obtained using RANS and DES.https://www.mdpi.com/2311-5521/4/3/148road vehicle aerodynamicsCFDturbulence modeling effectsRANShybrid LES/RANSDESexternal flow |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Chunhui Zhang Charles Patrick Bounds Lee Foster Mesbah Uddin |
spellingShingle |
Chunhui Zhang Charles Patrick Bounds Lee Foster Mesbah Uddin Turbulence Modeling Effects on the CFD Predictions of Flow over a Detailed Full-Scale Sedan Vehicle Fluids road vehicle aerodynamics CFD turbulence modeling effects RANS hybrid LES/RANS DES external flow |
author_facet |
Chunhui Zhang Charles Patrick Bounds Lee Foster Mesbah Uddin |
author_sort |
Chunhui Zhang |
title |
Turbulence Modeling Effects on the CFD Predictions of Flow over a Detailed Full-Scale Sedan Vehicle |
title_short |
Turbulence Modeling Effects on the CFD Predictions of Flow over a Detailed Full-Scale Sedan Vehicle |
title_full |
Turbulence Modeling Effects on the CFD Predictions of Flow over a Detailed Full-Scale Sedan Vehicle |
title_fullStr |
Turbulence Modeling Effects on the CFD Predictions of Flow over a Detailed Full-Scale Sedan Vehicle |
title_full_unstemmed |
Turbulence Modeling Effects on the CFD Predictions of Flow over a Detailed Full-Scale Sedan Vehicle |
title_sort |
turbulence modeling effects on the cfd predictions of flow over a detailed full-scale sedan vehicle |
publisher |
MDPI AG |
series |
Fluids |
issn |
2311-5521 |
publishDate |
2019-08-01 |
description |
In today’s road vehicle design processes, Computational Fluid Dynamics (CFD) has emerged as one of the major investigative tools for aerodynamics analyses. The age-old CFD methodology based on the Reynolds Averaged Navier−Stokes (RANS) approach is still considered as the most popular turbulence modeling approach in automotive industries due to its acceptable accuracy and affordable computational cost for predicting flows involving complex geometries. This popular use of RANS still persists in spite of the well-known fact that, for automotive flows, RANS turbulence models often fail to characterize the associated flow-field properly. It is even true that more often, the RANS approach fails to predict correct integral aerodynamic quantities like lift, drag, or moment coefficients, and as such, they are used to assess the relative magnitude and direction of a trend. Moreover, even for such purposes, notable disagreements generally exist between results predicted by different RANS models. Thanks to fast advances in computer technology, increasing popularity has been seen in the use of the hybrid Detached Eddy Simulation (DES), which blends the RANS approach with Large Eddy Simulation (LES). The DES methodology demonstrated a high potential of being more accurate and informative than the RANS approaches. Whilst evaluations of RANS and DES models on various applications are abundant in the literature, such evaluations on full-car models are relatively fewer. In this study, four RANS models that are widely used in engineering applications, i.e., the realizable <inline-formula> <math display="inline"> <semantics> <mrow> <mi>k</mi> <mo>−</mo> <mi>ε</mi> </mrow> </semantics> </math> </inline-formula> two-layer, Abe−Kondoh−Nagano (AKN) <inline-formula> <math display="inline"> <semantics> <mrow> <mi>k</mi> <mo>−</mo> <mi>ε</mi> </mrow> </semantics> </math> </inline-formula> low-Reynolds, SST <inline-formula> <math display="inline"> <semantics> <mrow> <mi>k</mi> <mo>−</mo> <mi>ω</mi> </mrow> </semantics> </math> </inline-formula>, and V2F are evaluated on a full-scale passenger vehicle with two different front-end configurations. In addition, both cases are run with two DES models to assess the differences between the flow predictions obtained using RANS and DES. |
topic |
road vehicle aerodynamics CFD turbulence modeling effects RANS hybrid LES/RANS DES external flow |
url |
https://www.mdpi.com/2311-5521/4/3/148 |
work_keys_str_mv |
AT chunhuizhang turbulencemodelingeffectsonthecfdpredictionsofflowoveradetailedfullscalesedanvehicle AT charlespatrickbounds turbulencemodelingeffectsonthecfdpredictionsofflowoveradetailedfullscalesedanvehicle AT leefoster turbulencemodelingeffectsonthecfdpredictionsofflowoveradetailedfullscalesedanvehicle AT mesbahuddin turbulencemodelingeffectsonthecfdpredictionsofflowoveradetailedfullscalesedanvehicle |
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