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Old 04-28-2020, 06:45 PM   #25 (permalink)
JulianEdgar
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Quote:
Originally Posted by COcyclist View Post
OP- Thank you for posting this. I especially liked the color representations in the full paper. There is one thing I would like to point out. In post #1 the graph you posted is from the averaged wind tunnel vs CFD results. I was shocked by the amount that front lift went up in the graph. As I read the whole article I found there was a discrepancy between wind tunnel and CFD results. The wind tunnel did not show such drastic increase in lift with the fully blanked wheel. I copied the following from the conclusions.

"Overall, CFD predicts the trends from the wind tunnel results well; however, in the case with the fully blanked wheels there is a noticeable over-shoot in the drag decrease and the front lift increase. CFD also fails to capture the drag trend for the smallest centre blanking (350mm), though it predicts the rear lift trend well. Based on these two cases, it is thought that CFD over-predicts the effects of the interactions between the onset flow and the flow through the front wheels."

The CFD was done without modeling turning wheels. Great article. Thanks.
As I said in Post #2, the graph displays the difference in CFD prediction vs wind tunnel results (ie the error) - not the actual changes in drag. The heading explains that - change of CD from CFD minus change in CD from wind tunnel.
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aerohead (04-29-2020), COcyclist (04-29-2020), freebeard (04-28-2020)