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A Comparison of On-Road Aerodynamic Drag Measurements with Wind Tunnel Data from Pininfarina and MIRA
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Abstract
The principal development tool for the vehicle aerodynamicist continues to be the full-scale wind tunnel. It is expected that this will continue for many years in the absence of a reliable alternative.
As a true simulation of conditions on the road, the conventional full-scale wind tunnel has limitations. For example, the ground is fixed relative to the vehicle, allowing an unrepresentative boundary layer to develop, and the wheels of the test vehicle do not rotate. These limitations are known to influence measured aerodynamic data.
In order to improve the representation of road conditions in the wind tunnel, most of the techniques used have attempted to control the ground plane boundary layer. Only at model scale has the introduction of a moving ground plane and rotating wheels been widely adopted.
The Pininfarina full-scale wind tunnel now incorporates the Ground Effect Simulation System which allows testing with a moving belt and rotating wheels. A major feature of this facility is that test vehicles can be easily installed with only minor modifications.
This paper compares aerodynamic drag measurements for a large saloon, in various configurations, obtained both in the wind tunnel and on the road. The wind tunnel results are presented for various ground simulations. These are: moving belt with rotating wheels and stationary belt with fixed wheels at Pininfarina, and the conventional fixed ground in the MIRA full-scale wind tunnel. The on-road data is derived from coastdown tests.
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Le Good, G., Howell, J., Passmore, M., and Cogotti, A., "A Comparison of On-Road Aerodynamic Drag Measurements with Wind Tunnel Data from Pininfarina and MIRA," SAE Technical Paper 980394, 1998, https://doi.org/10.4271/980394.Also In
References
- COGOTTI, A. Aerodynamic Characteristics of Car Wheels Int J. of Vehicle Design, Technological Advances In Vehicle Design 173 196 1983
- BONIS, B. Aerodynamics of Wheels and Tires Interface Vehicule-Sol/Road/ Vehicle Interface Monte-Carlo 23rd 25th January 1989
- 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. 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. BERNEBURG, H. On the Simulation Of Road Driving of a Passenger Car in a Wind Tunnel Using a Moving Belt and Rotating Wheels Proceedings of Florence ATA Conference 1992
- MERCKER, E. SOJA, H. WIEDEMANN, J. Experimental Investigation on the Influences of Various ground Simulation Techniques on a Passenger Car Proceedings of Vehicle Aerodynamics Conference The Royal Aeronautical Society Loughborough July 1994
- WIEDEMANN, J. The Influence of Ground Simulation and Wheel Rotation on Aerodynamic Drag Optimization - Potential for Reducing Fuel Consumption SAE Paper 960672 Detroit 1996
- WICKERN, G. ZWICKER, K. PFADENHAUER, M. Rotating Wheels - Their Impact on Wind Tunnel Test Techniques and on Vehicle Drag Results SAE Paper 970133 Detroit 1997
- COGOTTI, A. et al Comparison Tests Between Some Full-Scale European Automotive Wind Tunnels - Pininfarina Reference Car SAE Paper 800139 Detroit 1980
- BUCHHEIM, R. et al Comparison Tests Between Major European Wind Tunnels SAE paper 800140 Detroit 1980
- COSTELLI, A. et al. FIAT Research Centre Reference Car Correlation Tests Between Four Full Scale European Wind Tunnels and Road SAE Paper 810187 Detroit 1981
- CARR, G.W. Correlation of Aerodynamic Force Measurements in MIRA and Other Automotive Wind Tunnels SAE Paper 820374 Detroit 1982
- HOWELL, J.P. HAYNES, T.L. Wind Tunnel Correlation Rover Internal Report October 1991
- COGOTTI, A. Ground Effect Simulation for Full-Scale Cars in the Pininfarina Wind Tunnel SAE Paper 950996 Detroit 1995
- BUCKLEY, F. ABCD - An Improved Coast Down Test and Analysis Method SAE Paper 950626 Detroit 1995
- PASSMORE, M.A. LE GOOD, G.M. A Detailed Drag Study Using The Coastdown Method SAE Paper 940420 Detroit 1994
- GOOD, G.M. et al On-Road Aerodynamic Drag Measurements Compared With Wind Tunnel Data SAE Paper 950627 Detroit 1995
- MERCKER, E. WIEDEMANN, J. On the Correction of Interference Effects in Open Jet Wind Tunnels SAE Paper 960671 Detroit 1996
- COOPER., K.R. FEDIW, A.A. GARY, K.P. Development of a Moving Ground Belt System for the Study of Vehicle Aerodynamics Proceedings of Vehicle Aerodynamics Conference The Royal Aeronautical Society Loughborough July 1994
- CARR, G.W. Influence of Moving-Belt Dimensions on Vehicle Aerodynamic Forces Proceedings of MIRA International Vehicle Aerodynamics Conference Birmingham October 1996