Quote:
Originally Posted by jeff88
As long as your 'small' hole is 15% bigger than your radiator opening... 
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Aerohead, that car looks aeroynamically sound, but I don't see any extractors (or holes of any kind). Can you elaborate in layman's what they are doing? |
If you look directly above the front wheel,near where the windshield edge would be,you'll barely make out a slot which is oriented with the color dye solution.
I believe that there are corresponding slots below as well.
Morelli divided the cooling air coming out of the engine bay into 4-different streams and experimented with duct size and geometry such that the air escaping out these slots blended perfectly with the surrounding flow field.
An isobaric/velocity contour map was created by pressure tap and velocity pressure measurements (you see this today in color CFD mapping),and working with Bernouli's Theorem,arrived at duct sizes which provide the air volume at a matched velocity,given the pressure environment its flowing into.
This cannot be modeled analytically yet and must be done by trial and error in the tunnel.(very expensive!)
If you get it wrong:
*air can flow into the exits
*jets can be formed which trigger shear-induced vorticity,eddies,turbulence
*Transverse-vectored jets can contaminate the boundary layer,trigger separation,along with the formation of form additional vorticity.
My opinion is that 'nailing' this sort of thing is completely outside the scope of what individuals can pull off without major money.
*air can stall within the duct