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Old 05-11-2020, 06:03 PM   #10 (permalink)
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Originally Posted by JulianEdgar View Post
I am sorry, but that completely ignores the major reason that lift occurs on cars. The lift - especially rear lift - in most cars doesn't come from the wake (ie separated flow). It comes from the accelerating flows over the curved upper surfaces.

I am sorry, but that is wrong. An aerofoil has attached flow and can develop lift. You may choose to orientate a streamlined body (like an aerofoil) so it doesn't generate lift, but that is not the same as saying "streamline bodies are incapable of generating lift", as you previously wrote. In fact - of course - the best lifting bodies are streamlined.

I am sorry, but you are confusing cause and effect. You can be certain the upper surfaces of your car were developing lift. However, if the car in fact didn't develop overall lift, it would have been because of the low pressures developed under the car by its bellypan.

Note: all of this can be directly measured on real cars using a surface pressure disc (easy to make yourself), a Magnehelic gauge and a sealed reservoir.
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