How big should be the domain for an automotive external aerodynamics calculation  (Read 1045 times)

Offline infocfd

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How big should I make the domain for an automotive external aerodynamics calculation? I want to replicate wind tunnel test.

Offline william

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To replicate a wind tunnel test, you are obviously limited to the physical size of the wind tunnel lateral to the car. It is suggested to have at least two body-lengths upstream of the car for the inflow boundary and three body-lengths downstream of the car for the outflow boundary. As always, more is better, but it is not always cost-effective.

To replicate the vehicle on the open road, you can use the old rule-of-thumb from the wind tunnel testing of using a solid blockage of .5%. For example, the projected area of your car should be .5% of the total area of the inflow plane.