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Towards a Standardized Assessment of Automotive Aerodynamic CFD Prediction Capability - AutoCFD 2: Windsor Body Test Case Summary
Technical Paper
2022-01-0898
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
To improve the state of the art in automotive aerodynamic prediction using CFD, it is important to compare different CFD methods, software and modelling for standardized test cases. This paper reports on the 2nd Automotive CFD Prediction Workshop for the Windsor body squareback test case. The Windsor model has high quality experimental data available and a simple geometry that allows it to be simulated with limited computational resources. The model is 1 metre long and operates at a Reynolds number of 2.7 million. The original Windsor model did not include wheels, but a second variant was added here with non-rotating wheels. Experimental data is available for integrated forces, surface pressure and wake PIV surveys. Eight standard meshes were provided, covering the two geometry variants, two near wall mesh spacings (relating to wall resolved and wall modelled) and two mesh densities in the wake (relating to RANS and eddy resolving). The mesh sizes ranged from 3.3 to 50 million cells. 73 solutions were submitted from 17 organizations. The data was integrated into a web-based dashboard to allow any participant to interrogate and compare their results. There was significant variability in predicted lift, drag and moment coefficients, even when using the same turbulence model on the workshop provided grid. Most simulations underpredicted drag, but in general the eddy resolving simulations were closer to experiment. For centerline pressure, all the simulations gave a higher pressure than the experiment on the forward facing upper surface. All the RANS predictions showed incorrect, almost axisymmetric, base pressure distributions. The eddy resolving pressure distribution is much improved, reflecting the flatter distribution found in the experiment. Some simulations reported a left-right asymmetry in base pressure which is consistent with the experimentalists reporting a bi-stability of the wake for the no wheels case.
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Topic
Citation
Page, G. and Walle, A., "Towards a Standardized Assessment of Automotive Aerodynamic CFD Prediction Capability - AutoCFD 2: Windsor Body Test Case Summary," SAE Technical Paper 2022-01-0898, 2022, https://doi.org/10.4271/2022-01-0898.Also In
References
- Page , G.J. https://doi.org/10.17028/rd.lboro.18515087
- Page , G.J. https://doi.org/10.17028/rd.lboro.18515096
- Hupertz , B. , Lewington , N. , Mockett , C. , Ashton , N. , and Duan , L.
- Ahmed , S. , Ramm , G. , and Faltin , G. Some Salient Features Of The Time-Averaged Ground Vehicle Wake SAE Technical Paper 840300 1984 https://doi.org/10.4271/840300
- Le Good , G. and Garry , K. On the Use of Reference Models in Automotive Aerodynamics SAE Technical Paper 2004-01-1308 2004 https://doi.org/10.4271/2004-01-1308
- Strangfeld , C. , Wieser , D. , Schmidt , H. , Woszidlo , R. et al. Experimental Study of Baseline Flow Characteristics for the Realistic Car Model DrivAer SAE Technical Paper 2013-01-1251 2013 https://doi.org/10.4271/2013-01-1251
- Pavia , G. 2019 https://hdl.handle.net/2134/37524
- Pavia , G. and Passmore , M. Characterisation of Wake Bi-stability for a Square-Back Geometry with Rotating Wheels Wiedemann , J. Prog. Veh. Aerodyn. Therm. Manag Springer International Publishing 2018 93 109
- Varney , M. Base Drag Reduction for Squareback Road Vehicles Loughborough University 2020 https://doi.org/10.26174/thesis.lboro.11823759.v1
- Pavia , G. , Passmore , M. , Varney , M. , and Hodgson , G. Salient Three-Dimensional Features of the Turbulent Wake of a Simplified Square-Back Vehicle Journal of Fluid Mechanics 888 https://doi.org/10.1017/jfm.2020.71
- Varney , M. , Pavia , G. , Passmore , M. , and Crickmore , C. Windsor Model Experimental Aerodynamic Dataset Dataset Loughborough University 2020 https://doi.org/10.17028/rd.lboro.13161284
- Johl , G. , Passmore , M. , and Render , P. Design Methodology and Performance of an Indraft Wind Tunnel The Aeronautical Journal 108 2004 https://doi.org/10.1017/S0001924000001810
- https://streamlit.io
- Rumsey , C. , Smith , B. , and Huang , G. https://turbmodels.larc.nasa.gov