This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Underbody aerodynamics: Drag coefficient reduction in road vehicles
Technical Paper
2018-36-0291
ISSN: 0148-7191, e-ISSN: 2688-3627
This content contains downloadable datasets
Annotation ability available
Sector:
Language:
English
Abstract
In the last decades it has been constantly debated about the behaviour of the human being towards a better usage of the natural resources through a restructuring of unsustainable processes. Considering the case for road vehicles, it was noticed a potential for improvement by assigning a more “harmonious” configuration to the underbody of the vehicles, in order to contribute to the reduction of aerodynamic drag. This region of the vehicles is often overlooked by the automakers because it is not easily accessible to the eyes of the consumer. The objective of this paper is, therefore, to improve the aerodynamic performance of the underbody region of a compact hatchback car available in the Brazilian market. This project proposes a new underbody configuration that promotes a more harmonious flow under the vehicle, reducing this way the drag coefficient (Cd) hence improving the fuel consumption. A comparative analysis, therefore, was performed between the standard condition of the underbody (baseline) and the experimental configuration by the fluid flow simulation of the tridimensional models using a Computational Fluid Dynamics (CFD) software. Both analysis can be divided in three main stages: the tridimensional geometry modeling in CAD software, the model discretization (the creation of the computational domain and boundary conditions using a mesh generator) and the fluid flow solution in CFD. Based on the analysis of the results obtained for the fluid flow on the baseline, panels (belly pans) were proposed to cover the underbody of the vehicle. This experimental condition presented a reduction on the local drag coefficient, that is, considering only the underbody, of 28,4% and, considering the complete vehicle, of 13%. The total drag coefficient with the proposed panels was reduced from 0.34 to 0.296, which would make the studied model the vehicle with the lowest Cd of its category (compact hatchback) available in the Brazilian market.
Authors
Topic
Citation
Heidemann Jr, R., Rodrigues, A., Bohrer, A., Gertz, C. et al., "Underbody aerodynamics: Drag coefficient reduction in road vehicles," SAE Technical Paper 2018-36-0291, 2018, https://doi.org/10.4271/2018-36-0291.Data Sets - Support Documents
Title | Description | Download |
---|---|---|
Unnamed Dataset 1 | ||
Unnamed Dataset 2 |
Also In
References
- Gillespie , T. D. Fundamentals of Vehicle Dynamics SAE Warrendale 1992
- Hucho , W. H. Aerodynamics of Road Vehicles 4th SAE International 1998
- Buchheim , R. , Leie , B. , Lückoff , H.-J. , Der Neue Audi 100 - Ein Beispiel für konsequente aerodynamische Personenwagen- Entwicklung ATZ 85 1983
- Kerschbaum , H. , Reifenuntersuchungen am BMW 318i BMW Inc 1991
- Wickern , G. , Zwicker , K. , Pfadenhauer , M. Rotating Wheels - Their Impact on Wind Tunnel Test Techniques and on Vehicle Drag Results SAE International 1997
- Rehnberg , S. , Koitrand , S. A computational investigation of Wheel and Underbody Flow Interaction Chalmers University of Technology, Department of Applied Mechanics 2013
- Katz , J. Race Car Aerodynamics Bentley Publishers 1995
- Anderson Jr , J. Fundamentals of Aerodynamics 4th. McGraw-Hill 2007
- Ansys Fluent . ANSYS FLUENT Theory Guide: Version 14.0 Canonsburg, ANSYS Inc. 2012