This content is not included in your SAE MOBILUS subscription, or you are not logged in.
The Influence of Ground Simulation and Wheel Rotation on Aerodynamic Drag Optimization - Potential for Reducing Fuel Consumption
ISSN: 0148-7191, e-ISSN: 2688-3627
Published February 01, 1996 by SAE International in United States
Annotation ability available
In automobile development, wind tunnel measurements are used to optimize fuel consumption and the vehicle's road behavior. The classic measuring technique is based on a stationary vehicle set up in the wind tunnel with stationary wheels. Relative movement between vehicle and road surface is therefore ignored. In more recent studies, measurements have been taken with improved ground simulation. For example, a belt is used instead of the stationary wind tunnel floor and the car wheels rotate.
Ground simulation using a belt and rotating wheels generally leads to a reduction in flow angularity at the front wheels, in the same way as blocking the cooling air flow, whereby, as a matter of fact, the aerodynamic drag is reduced. Analogous air flow angle correlations can be established for the effect of underfloor panels. Thus, ground simulation affects local flow quantities as well as total air flow values, not only with regard to the absolute drag coefficient, but also to differential measurements governed by the configuration. The classic measuring technique in certain cases, leads to a change in the sign of ΔcD when assessing optimization measures.
In conclusion, correlations between reductions in drag and fuel consumption are established. The rule of thumb is that, in the case of optimization measures which have such a minimal influence on weight that the car's inertial mass category remains the same, a reduction in drag, e.g. by 1 % ΔcD≈0.003), has the same effect on fuel consumption in the European MVEG II cycle as an equally large reduction in weight (10-15 kg).
CitationWiedemann, J., "The Influence of Ground Simulation and Wheel Rotation on Aerodynamic Drag Optimization - Potential for Reducing Fuel Consumption," SAE Technical Paper 960672, 1996, https://doi.org/10.4271/960672.
Vehicle Aerodynamics: Wind Tunnels, Cfd, Aeroacoustics, and Ground Transportation Systems
Number: SP-1145; Published: 1996-02-01
Number: SP-1145; Published: 1996-02-01
- R. V. KOENIG-FACHSENFELD Aerodynamik des Kraftfahrzeugs Vol. I and II, Vol. III and IV Umschau-Verlag Frankfurt 1951
- KIESELBACH R. J. F. Stromlinienautos in Deutschland, Aerodynamik im PKW-Bau 1900-1945 Kohlhammer-Verlag 1982
- HUCHO W.-H (Hrsg.) Aerodynamik des Automobils Vogcl-Verlag 1981
- HACKETT J.E. WILLIAMS J.E. BAKER J.B. WALLIS S. B. On the Influence on Ground Movement and Wheel Rotation in Tests of Modern Car Shapes SAE Paper 870245 Detroit 1987
- MERCKER E. KNAPE H.W. Ground Simulation With Moving Belt and Tangential Blowing for Full-Scale Automotive Testing in a Wind Tunnel SAE Paper 890367 Detroit 1989
- MERCKER E. BERNEBURG H. Über die Simulation dcr Straβenfahrt eincs PKW in einem Windkanal durch bewegten Boden und drehende Räder Conference Nr. T-30-341-056-2 “Aerodynamik des Kraftfahrzeugs” Haus der Technik, Essen 1992
- MERCKER E. BREUER N. BERNEBURG H. EMMELMANN H-J. On the Aerodynamic Interference Due to the Rolling Wheels of Passenger Cars SAE Paper 910311 Detroit 1991
- MERCKER E. SOJA H. WIEDEMANN J. Experimental Investigation on the Influence of Various Ground Simulation Techniques on a Passenger Car Conference Proceeding “Vehicle Aerodynamics” The Royal Aeronautical Society Loughborough, U.K. July (1994)
- KLEMIN A. A Belt Method of Representing the Ground J. Aero. Sciences 1 198 199 October 1934
- CARR G. W. A Comparison of the Ground-Plane-Suction and Moving-Belt Ground-Representation Techniques SAE Paper 880249 Detroit 1988
- BERNDTSSON A. ECKERT W.T. MERCKER E. The Effects of Groundplane Boundary Layer Control on Automotive Testing in a Wind Tunnel SAE Paper 880248 Detroit 1988
- BEARMAN P.W. DE BEER D. HAMIDY E. HARVEY J.K. The Effect of a Moving Floor on Wind-Tunnel Simulation of Road Vehicles SAE Paper 880245 Detroit 1988
- NILSSON. L. U. BERNDTSSON A. KNUTSON K. DANIELSON H. A Study of Ground Simulation - Correlation between Wind Tunnel and Water-Basin Tests of a Full-Scale Car SAE Paper 890368 Detroit 1989
- COOPER K. R. FEDIW A. A. GARRY K. P. WLODARSKY S. Development of a Moving Ground System for the Study of Vehicle Aerodynamics Conference Proceeding “Vehicle Aerodynamics” The Royal Aeronautical Society Loughborough, U.K. July (1994)
- WIEDEMANN J. Some Basic Investigations into the Principles of Ground Simulation Techniques in Automotive Wind Tunnels SAE Paper 890369 Detroit 1989
- MERCKER E. WIEDEMANN J. Comparison of Different Ground Simulation Techniques for Use in Automotive Wind Tunnels SAE Paper 900321 Detroit 1990
- WIEDEMANN J. On the Importance of Ground Simulation for the Optimisation of the Underside of Passenger Cars. CNR - Pininfarina - Workshop “Ground Effect Simulation of Road Vehicles in Automotive Wind Tunnels” Turin 1994
- GÖRGE W. Private Communication AUDI AG 1994
- RINKE K.-P. Private Communication AUDI AG 1994
- PFADENHAUER M. Konzepte zur Verringerung des Luftwiderstandsbeiwertes von Personenkraft-wagen unter Berücksichtigung der Wechsel-wirkungen zwischen Fahrzeug und Fahrbahn sowie der Raddrehung Diploma Project, Report FLM 95/33, Lehrstuhl für Fluidmechanik Technical University Munich 1995
- WIEDEMANN J. SETTGAST W. Der Einfluβ der Bodensimulation auf die Optimierung des Lufhviderstandes - Vergleich von Windkanal und Straβe - Potential für Verbrauchreduzierungen Stuttgarter Symposium Institut für Verbrennungs-motoren und Kraftfahrwesen der Universität Stuttgart 1995