Aerodynamic Investigation of Vehicle Cooling-Drag

2012-01-0170

04/16/2012

Event
SAE 2012 World Congress & Exhibition
Authors Abstract
Content
The interaction between cooling-air and external aerodynamics is known as interference. In a conventional car this interference under the hood results in additional drag. It is estimated that about 10% of the overall aerodynamic drag originates from the cooling air [1] depending on the car shape and cooling configuration. Obviously, cooling drag should be minimized for vehicles with low-drag aerodynamics. In this study cooling-air interference-effects are investigated through experimental, numerical and analytical methods with a focus on the surface pressure of the vehicle. The surface pressure of vehicles with and without interference effects is compared. Observations show that when the cooling-air inlet is opened a pressure rise occurs around the inlet, while a pressure drop appears around the outlet. This phenomenon was investigated for several vehicle shapes including a simplified bluff-body (SAE-Body) and a close-to-real quarter-scale model (aeromodel). Using this knowledge, a cooling duct with low cooling drag was investigated. It will be shown that the cooling drag decreases when the air is redirected appropriately, yet the pressure increase at the front of the vehicles cannot be avoided.
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DOI
https://doi.org/10.4271/2012-01-0170
Pages
11
Citation
Baeder, D., Indinger, T., Adams, N., and Unterlechner, P., "Aerodynamic Investigation of Vehicle Cooling-Drag," SAE Technical Paper 2012-01-0170, 2012, https://doi.org/10.4271/2012-01-0170.
Additional Details
Publisher
Published
Apr 16, 2012
Product Code
2012-01-0170
Content Type
Technical Paper
Language
English