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Automobile Aerodynamic Drag on the Road Compared With Wind Tunnel Tests
ISSN: 0148-7191, e-ISSN: 2688-3627
Published February 01, 1981 by SAE International in United States
Annotation ability available
This investigation was performed with the purpose of comparing the arodynamic drag of an automobile as measured in a full-scale wind tunnel with the drag as measured on the road. A definition of the drag coefficient as measured both on the road and in the wind tunnel is given in advance in order to allow a comparison to be made between the two operating conditions. Three medium size european cars were selected, one notch-back type and two hatch-back types. Road testing was mainly based on the coast-down method. The total resistance was determined by statistical analysis of the experimental results. The theoretical basis and the specifications of the procedure are investigated and justified. Additional outdoor and indoor tests were carried out in order to isolate the aerodynamic drag. The wind tunnel tests were conducted on the same cars fully equipped as tested on the road and in the same speed range. The wind tunnel tests being executed at steady speeds, however, supplementary road tests were performed in order to determine the effect of the deceleration on the aerodynamic drag. The final results show only small differences between the aerodynamic drag coefficients as measured in the wind tunnel and on the road with the procedure here described.
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CitationMorelli, A., Nuccio, P., and Visconti, A., "Automobile Aerodynamic Drag on the Road Compared With Wind Tunnel Tests," SAE Technical Paper 810186, 1981, https://doi.org/10.4271/810186.
- Morelli A. “Aerodynamic Actions on an Automobile Wheel” Symposium on Road Vehicle Aerodynamics City University-London 1969 5/1 5/9
- Rodden W.P. Giesing J.P. “Application of Oscillatory Aerodynamic Theory to Estimation of Dynamic Stability Derivatives” J. Aircraft 7 3 1970
- Bucheim R. et al. “Comparison Tests Between Major European Automotive Wind Tunnels” SAE Congress paper No. 800140 - Detroit, MI February 1980
- Cogotti A. et al. “Comparison Tests Between Some Full-Scale European Automotive Wind Tunnels - Pininfarina Reference Car” SAE Congress paper No. 800139 - Detroit, MI February 1980
- Costelli A. Garrone A. et al. “FIAT Research Center Reference Car-Correlation Tests Between Four Full-Scale European Wind Tunnels and Road” SAE Congress Detroit, MI February 1981
- Larrabee E. “Determination of Aerodynamic Drag from Coast-Down Tests” Symposium on Road Vehicle Aerodynamics BHRA - Cranfield (GB) January 1973
- Korst H.H. White R.A. “Aerodynamic and Rolling Resistance of Vehicles as Obtained from Coast-Down Experiments” Proc., 2nd Int. Conf. on Vehicle Mech. Paris. Swets and Zeitlinger, B.V. Amsterdam 6-9 September 1971 146 160
- Roussillon G. Marzin J. Bourbis J. “Contribution to the Accurate Measurement of the Aerodynamic Drag by the Deceleration Method” BHRA Symposium Cranfield (GB) January 1973 53 63
- Korst H.H. White R.A. “Evaluation of Vehicle Drag Parameters from Coast-Down Experiments Conducted under Non-Ideal Environmental Conditions” ASME Conference on Aerodynamics of Transportation Niagara Falls, N.Y. June 1979 229 240
- Fogg A. “Measurement of Aerodynamic Drag and Rolling Resistance of Vehicles” X FISITA Congress Tokyo May 1964
- Carr G.W. Rose M.J. “The M.I.R.A. Single-Wheel Rolling Resistance Trailers” M.I.R.A. Report No. 1966/5
- Cugiani C. Piazzo C. “Sistema di Radiorilevamento ad Interferenza nella Banda ‘S’. Criteri Seguiti nel Progetto e Valutazione dell'Errore di Spazio” Alta Frequenza Revue (I) 4 XLIII 1974 207 210