This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Effects of Ground Simulation on the Aerodynamic Coefficients of a Production Car in Yaw Conditions
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 12, 2010 by SAE International in United States
Annotation ability available
Automotive wind tunnel testing is a key element in the development of the aerodynamics of road vehicles. Continuous advancements are made in order to decrease the differences between actual on-road conditions and wind tunnel test properties and the importance of ground simulation with relative motion of the ground and rotating wheels has been the topic of several studies.
This work presents a study on the effect of active ground simulation, using moving ground and rotating wheels, on the aerodynamic coefficients on a passenger car in yawed conditions. Most of the published studies on the effects of ground simulation cover only zero yaw conditions and only a few earlier investigations covering ground simulation during yaw were found in the existing literature and all considered simplified models. To further investigate this, a study on a full size sedan type vehicle of production status was performed in the Volvo Aerodynamic Wind Tunnel. The effect of active ground simulation in yawed wind conditions was investigated for different wheel and cooling air inlet configurations.
Results show that aerodynamic drag increased more during yaw when using active ground simulation compared to stationary ground conditions. For some of the configurations this resulted in yaw ranges where active ground simulation produced higher aerodynamic drag than with stationary ground. This was mainly connected to the development of the front wheel wakes and the deflection of the windward wheel wake along the underbody during yaw. Aerodynamic lift generally decreased but the front and rear lift balance changed somewhat during yaw for some configurations. Local surface pressure measurements were used to identify important flow field changes and the integrated surface pressures showed a qualitative agreement with the measured drag and lift.
CitationLandström, C., Walker, T., and Löfdahl, L., "Effects of Ground Simulation on the Aerodynamic Coefficients of a Production Car in Yaw Conditions," SAE Technical Paper 2010-01-0755, 2010, https://doi.org/10.4271/2010-01-0755.
- Hucho W-H “Aerodynamics of Road Vehicles 4th 0-7680-0029-7 USA 1998
- Hucho W. H. “Aerodynamik des Automobiles, 5. Auflage” 0-7680-0029-7 2005
- Landström C. Walker T. Löfdahl L. “Initial Experimental Investigation of the Local Flow Field Around Rotating Wheels using an Omni-probe” 7th MIRA International Vehicle Aerodynamics Conference 15-16 October Warwickshire, UK 2008
- Landström C. Löfdahl L. Walker T. “Detailed Flow Studies in Close Proximity of Rotating Wheels on a Passenger Car” SAE Int J. of Pass. Cars - Mech. Sys. 2 1 861 874 2009
- Christofferesen L. Quartey-Papafio R. Landström C. Löfdahl L. Jönson A. “Influence of Moving Ground Conditions on the Cooling Flows of Road Vehicles” 26th AIAA Applied Aerodynamics Conference Honolulu, Hawaii 2008
- Wiedemann J. “The Influence of Ground Simulation and Wheel Rotation on Aerodynamic Drag Optimization - Potential for Reducing Fuel Consumption” SAE Technical Paper 960672 1996
- Wäschle A. “The Influence of Rotating Wheels on Vehicle Aerodynamics - Numerical and Experimental Investigations” SAE Technical Paper 2007-01-0107 2007
- Elofsson P. Bannister M. “Drag Reduction Mechanisms Due to Moving Ground and Wheel Rotation in Passenger Cars” SAE Technical Paper 2002-01-0531 2002
- Mercker E. Bernerburg H. “On the Simulation of Road Driving of a Passenger Car in a Wind Tunnel Using Moving Belt and Rotating Wheels” 3rd Int. Conf. Innovation and Reliability Florence April 8-10 1992
- Mercker E. Breuer N. Berneburg H. Emmelmann H.J. “On the Aerodynamic Interference Due to the Rolling Wheels of Passenger Cars” SAE Technical Paper 910311 1991
- Wickern G. Zwickern K. Pfadenhauer M. “Rotating Wheels - Their Impact on Wind Tunnel Test Techniques and on Vehicle Drag Results” SAE Technical Paper 970133 1997
- Wickern G. Wagner A. Zoerner C. “Cooling Drag of Ground Vehicles and Its Interaction with Ground Simulation” SAE Technical Paper 2006-01-0339 2006
- Cogotti A. “Ground Effect of a Simplified Car Model in Side-Wind and Turbulent Flow” SAE Technical Paper 1999-01-0652 1999
- Söderblom, D. Elofsson, P. Hjelm, L. Löfdahl, L. “An Investigation of the Aerodynamic Drag Mechanisms due to Ground Simulation in Yawed Flow Conditions for Heavy Trucks” ASME FEDSM2009, FEDSM2009-78519 Vail, Colorado 2009
- Cooper K.R. Watkins S. “The Unsteady Wind Environment of Road Vehicles, Part One: A Review of the On-road Turbulent Wind Environment” SAE Technical Paper 2007-01-1236 2007
- Wordley S. Saunders J. “On-Road Turbulence: Part 2” SAE Technical Paper 2009-01-0475 2009
- SAE International “Crosswind Facilities and Procedures” SAE SP-1109 1995
- Sternéus J. Walker T. Bender T. “Upgrade of Volvo Cars Aerodynamic Wind Tunnel” SAE Technical Paper 2007-01-1043 2007
- Cogotti. A. “Contribution to the Understanding of a Passenger Car Behavior in Crosswind Conditions, by the Analysis of its Wake” SAE SP-1109