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Corrections for the Pressure Gradient Effect on Vehicle Aerodynamic Drag
Technical Paper
2003-01-0935
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Effects of the pressure gradient in the wind tunnel test section on vehicle aerodynamic drag were investigated using computational fluid dynamics (CFD). The numerical study was used to obtain the aerodynamic drag of several vehicles in two virtual wind tunnels, one with a zero pressure gradient and another with a nonzero (but small) pressure gradient. A comparison of the vehicle aerodynamic drags in these two virtual wind tunnels, and investigation of the physical mechanisms causing these differences, have led to two correction formulas. These formulas can be used to correct for the pressure gradient effect on vehicle aerodynamic drag measurement in a wind tunnel that has a nonzero pressure gradient. In the first formula, the correction is given explicitly in terms of known variables. The correction is 80% accurate for passenger car, sports car, sports utility vehicle (SUV), and is 70% accurate for pickup truck. In the second formula, the correction is more accurate, but is more involved with vehicle aerodynamic computations carried out twice, in wind tunnels with and without the pressure gradient. The CFD methodology used in the present can also be applied to generate other wind tunnel corrections.
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Authors
Citation
Yang, Z., Schenkel, M., and Fadler, G., "Corrections for the Pressure Gradient Effect on Vehicle Aerodynamic Drag," SAE Technical Paper 2003-01-0935, 2003, https://doi.org/10.4271/2003-01-0935.Also In
SAE 2003 Transactions Journal of Passenger Cars - Mechanical Systems
Number: V112-6; Published: 2004-09-15
Number: V112-6; Published: 2004-09-15
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