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A New Approach to Analyzing Cooling and Interference Drag

Journal Article
ISSN: 1946-3995, e-ISSN: 1946-4002
Published April 12, 2010 by SAE International in United States
A New Approach to Analyzing Cooling and Interference Drag
Citation: Tesch, G., Demuth, R., and Adams, N., "A New Approach to Analyzing Cooling and Interference Drag," SAE Int. J. Passeng. Cars – Mech. Syst. 3(1):339-351, 2010,
Language: English


This paper presents a new approach to analyzing and developing low-drag cooling systems. A relation is derived which describes cooling drag by a number of contributions. Interference drag clearly can be identified as one of them. Cooling system parameters can be assigned to different terms of the relation, so that differences due to parameter variations of the individual drag contributions can be estimated.
In order to predict the interference-drag dependency on the outlet location and the local outlet mass flow, an extensive study on a standard BMW sedan has been carried out, both experimentally and by CFD. The results show the importance of providing consistent outflow conditions which take into account the outlet location and flow direction, in order to minimize cooling drag.