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On the Underbody Flow of a Simplified Estate
Technical Paper
2000-01-0485
ISSN: 0148-7191, e-ISSN: 2688-3627
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Event:
SAE 2000 World Congress
Language:
English
Abstract
The demand for more energy efficient vehicles is driven by environmental considerations and alternative engine technology. In order to reduce fuel consumption on future vehicles the power needed to propel the car has to be lowered. Hence, considerable efforts are needed to improve the aerodynamics. For a modern vehicle the potential for further improvements on drag is mainly to be found in the underbody region, Howell (1991). This requires more knowledge of the underbody flow and the flow around the wheels.
In the present work the flow in the underbody region has been studied using a combination of experiments and calculations to obtain a more comprehensive database.
The model chosen for this work was the so called ASMO model from Daimler Benz, which is a well known geometry that is available for the public on the internet. A simple model was preferred since the goal was to study the basic mechanisms behind drag generated by the underbody flow.
The aerodynamics of this model was studied by analyzing how forces, pressure distributions and velocity fields varied for different configurations with and without wheel segments. The analysis shows that a major contribution to the overall drag on this model originates from the rear wheel segments.
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Citation
Aronson, D., Brahim, S., and Perzon, S., "On the Underbody Flow of a Simplified Estate," SAE Technical Paper 2000-01-0485, 2000, https://doi.org/10.4271/2000-01-0485.Also In
References
- Axelsson N. Ramnefors, M. Gustavson R. ‘Accuracy in computational aerodynamics, Part 1: Stagnation pressure’ SAE 980037 1998
- Carr G. W. ‘New MIRA drag reduction prediction method for cars.’ Automotive Engineer June July 1987
- Cooper K.R. Bertenyi T. Dutil G. Syms J. Sovran G *The aerodynamic performance of automotive underbody diffusers’ SAE 980030 1998
- Howell J.P. ‘The influence of a vehicle underbody on aerodynamic drag’ Autotech Congress Paper No. C427/6/032 Birmingham 1991
- Howell J.P. ‘The influence of ground simulation on the aerodynamics of simple car shapes with an underfloor diffuser’ Conference on vehicle aerodynamics Royal aeronautical society July 1994
- Hucho W.-H. ‘Aerodynamics of road vehicles’ SAE 0-7680-0029-7 1998
- Mercker, E Breuer N. Berneburg H. Emmelmann H.J. ‘On the aerodynamic interference due to the rolling wheels of passenger cars.’ SAE 910311 1991
- Perzon S. Sjögren T. Jönson A. ‘Accuracy in computational aerodynamics, Part 2: Base pressure’ SAE 980038 1998
- Ramnefors M. Bensryd R. Holmberg E Perzon S. ‘Accuracy of drag predictions on cars using CFD - effect of grid refinement and turbulence models’ SAE 960681 1996
- Shih, T. H. Zhu, J. Lumley, J. L. 1993 A realizable Reynolds stress algebraic equation model NASA tech. Memo. 105993
- Wickern G. Zwicker K. Pfadenhauer M. ‘Rotating wheels-their impact on windtunnel test techniques and on vehicle drag result’ SAE 970133 1997
- Wiedemann J. ‘The influence of ground simulation and wheel rotation on aerodynamic drag optimization - Potential for reducing fuel consumption’ SAE Tech. paper 960676 1996