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Old 01-26-2012, 07:53 PM   #4 (permalink)
aerohead
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mesh

Quote:
Originally Posted by Blacktree View Post
I've heard of some cars (from Mercedes, I think?) that have metal mesh on the underbody, to act as a belly pan of sorts. In a way, it makes sense. Because the mesh is slicing through the air edgeways, instead of hitting it full-face. Thoeretically, that would make it act as a "virtual solid" aerodynamically.

I doubt the mesh would be as effective as a solid surface, though. But it should be better than nothing. And expanded aluminum mesh can be had at the hardware store pretty cheap (and lightweight).

The idea here wouldn't necessarily be to build a complete belly pan from metal mesh, just the parts that are near hot spots, like the exhaust system.

Has anyone tried this yet? A search didn't yield anything.
If you go all the way to the back of Hucho's book,in the chapter on Numerical Analysis,he makes mention that air cannot support a load of any kind and will simply deform,attempting to reach equilibrium.
When the Big Dogs do 3-D CFD on cars,they will actually 'panel the wake',setting up the spherical vector coordinates of the wake as if it were a solid body to enable the inviscid flow protocals to function.Quite a challenge when there is no 'a priori' knowledge of how a theoretical cars wake will actually behave.
All this suggests that it requires a solid surface to alter airflow.
********* Here's the caveat for a belly pan though.If the rear valance is low enough to trap and pool dead air below it,for the entire length of the cars underside,a permeable membrane might aid in damping pressure oscillations underneath there.
There may be research published on such a thing.I don't know.So far,automakers are using solid panels,shielding heat sources.
If you have the inclination and want to do some sweat-philanthropy,do the mod and let us know.
You will need an exquisite baseline database for the vehicle for which to compare before and after.
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