Comparative Analysis of Turbulence Models for Automotive Aerodynamic Simulation and Design

Igali, Dastan; Mukhmetov, Olzhas; Zhao, Yong; Fok, S.C.; Teh, Soo Lee

doi:10.1007/s12239-019-0107-7

Cited by 25 publications

(21 citation statements)

References 11 publications

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“…Thus, it is important to optimize the aerodynamic shape of the car properly to minimize fuel consumption. Pressure drag and friction drag are the most important factors in aerodynamic design [3]. Aerodynamic drags can be minimized through geometry and flow modification of the vehicle since the geometry of the car is considered as one of the main factors affecting the drags [4].…”

Section: Introductionmentioning

confidence: 99%

An URANS Simulation of the Kelvin-Helmholtz Aerodynamic Effect over the Ahmed Body

Sadykov

Khalimov

Kylyshbek

et al. 2021

International Journal of Automotive Science and Technology

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The reduction of energy consumption of cars is always a significant issue in automotive design. Turbulent flow around a car body is very difficult to simulate accurately due to the complexity of the flow conditions around the body, such as complex flow separation and laminar to turbulent flow transition. In particular, flow over the Ahmed body with a rear angle of 25o is considered a challenging problem for the RANS approach with two-equation turbulence models. In this study, we aim to analyze the Kelvin-Helmholtz instability associated with this flow with a URANS approach. Methodology for utilizing the URANS method is fully discussed. The predicted velocity profiles and drag coefficient are com-pared with experimental results. Three turbulence models, such as the k-ε, k-ω and SST models, are assessed and validated with experimental data. The aim of the study is to evaluate the performance of these models for the study of the Kel-vin-Helmholtz instability over the Ahmed body and for car bodies generally us-ing experimental data for their validations. It is found that the URANS approach with the turbulence models with proper numerical treatment can perform as well as or even better than the LES. And the SST model shows the best performance compared with other turbulence models.

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Section: Introductionmentioning

confidence: 99%

An URANS Simulation of the Kelvin-Helmholtz Aerodynamic Effect over the Ahmed Body

Sadykov

Khalimov

Kylyshbek

et al. 2021

International Journal of Automotive Science and Technology

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“…There are many published studies in the literature that present the results of simulations aimed to provide insight into the flow around the Ahmed body. For example, two recent studies showed the wake structures of the vehicle in detail by Igali et al [5] and Sadykov et al [8], respectively, with the former using the RANS approach and the latter the URANS one. Their usefulness is in the comparison of results obtained by the RANS and URANS approaches with different turbulence models, where Igali et al [5] achieved 2.474% of error in comparison with experimentally measured drag coefficient using the RANS approach, while Sadykov et al [8] obtained 1.68% error using the URANS method.…”

Section: Literature Reviewmentioning

confidence: 99%

“…For example, two recent studies showed the wake structures of the vehicle in detail by Igali et al [5] and Sadykov et al [8], respectively, with the former using the RANS approach and the latter the URANS one. Their usefulness is in the comparison of results obtained by the RANS and URANS approaches with different turbulence models, where Igali et al [5] achieved 2.474% of error in comparison with experimentally measured drag coefficient using the RANS approach, while Sadykov et al [8] obtained 1.68% error using the URANS method. Moreover, each of the papers has a detailed flow visualization of the wake region at the back of the vehicle model.…”

Section: Literature Reviewmentioning

confidence: 99%

“…As a result, Both LES and DES have very high computation costs, which hinders the practical application of DES and LES for high Reynolds number flows around Ahmed Body [13] for ADO. It is also noteworthy that Igali et al [5] and Sadykov et al [8] showed that the RANS and URANS As a result, it can capture the turbulent eddies near and at the rear of the Ahmed Body, which is crucial for properly capturing the Kelvin-Helmholtz instability of shear layers there. However, as the VLES model is a relatively new approach, there are no crucial studies that have been performed to evaluate its performance and efficiency for its potential application in Aerodynamic Design Optimization (ADO) for automotive vehicles.…”

Section: Literature Reviewmentioning

confidence: 99%

“…A typical benchmark case widely used for flow model validation in the automotive industry is the experimental study by Ahmed et al [4], where they performed an experiment in a wind tunnel using the Ahmed body as a simplified vehicle model. Igali et al [5] used the Ahmed body as a test case to compare the performance and efficiency of different turbulence models for automotive aerodynamic application and concluded that the RANS approach with the k-ω SST model is still sufficiently accurate in calculating the time-averaged parameters in contrast to the earlier general claim of the model's inability to capture the Kelvin-Helmholtz effect adequately by Menter [6], the inventor of the model.…”

Section: Introductionmentioning

confidence: 99%

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An Arbitrary Hybrid Turbulence Modeling Approach for Efficient and Accurate Automotive Aerodynamic Analysis and Design Optimization

Maulenkul

Yerzhanov

Kabidollayev

et al. 2021

Fluids

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The demand in solving complex turbulent fluid flows has been growing rapidly in the automotive industry for the last decade as engineers strive to design better vehicles to improve drag coefficients, noise levels and drivability. This paper presents the implementation of an arbitrary hybrid turbulence modeling (AHTM) approach in OpenFOAM for the efficient simulation of common automotive aerodynamics with unsteady turbulent separated flows such as the Kelvin–Helmholtz effect, which can also be used as an efficient part of aerodynamic design optimization (ADO) tools. This AHTM approach is based on the concept of Very Large Eddy Simulation (VLES), which can arbitrarily combine RANS, URANS, LES and DNS turbulence models in a single flow field depending on the local mesh refinement. As a result, the design engineer can take advantage of this unique and highly flexible approach to tailor his grid according to his design and resolution requirements in different areas of the flow field over the car body without sacrificing accuracy and efficiency at the same time. This paper presents the details of the implementation and careful validation of the AHTM method using the standard benchmark case of the Ahmed body, in comparison with some other existing models, such as RANS, URANS, DES and LES, which shows VLES to be the most accurate among the five examined. Furthermore, the results of this study demonstrate that the AHTM approach has the flexibility, efficiency and accuracy to be integrated with ADO tools for engineering design in the automotive industry. The approach can also be used for the detailed study of highly complex turbulent phenomena such as the Kelvin–Helmholtz instability commonly found in automotive aerodynamics. Currently, the AHTM implementation is being integrated with the DAFoam for gradient-based multi-point ADO using an efficient adjoint solver based on a Sparse Nonlinear optimizer (SNOPT).

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AeroINR: Meta-learning for Efficient Generation of Aerodynamic Geometries

Bamford,

Toal,

Keane

2024

Lecture Notes in Computer Science

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Comparative Analysis of Turbulence Models for Automotive Aerodynamic Simulation and Design

Cited by 25 publications

References 11 publications

An URANS Simulation of the Kelvin-Helmholtz Aerodynamic Effect over the Ahmed Body

An URANS Simulation of the Kelvin-Helmholtz Aerodynamic Effect over the Ahmed Body

An Arbitrary Hybrid Turbulence Modeling Approach for Efficient and Accurate Automotive Aerodynamic Analysis and Design Optimization

AeroINR: Meta-learning for Efficient Generation of Aerodynamic Geometries

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