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How Is Cd,0 Estimated?

Posted: Mon Sep 19, 2005 11:25 am
by lehpron
Am I correct to infer that Reynold's number is involved in estimating the zero-lift coefficient? I know how do estimate it for plates, what about 3D objects? I have no darn clue how the heck to even start. Any insight is greatly appreciated, thank you.

RE: How Is Cd,0 Estimated?

Posted: Mon Sep 19, 2005 12:06 pm
by 3201
See if this helps. (It says to use the fuselage length for the fuselage, the nacelle length for the nacelles, etc.... no magic. But there's more info there that might be useful for these kinds of calculations.)

RE: How Is Cd,0 Estimated?

Posted: Mon Sep 19, 2005 10:37 pm
by zeke
Quoting Lehpron (Thread starter):
I have no darn clue how the heck to even start.

Neither did anyone else. So a whole lot of wind tunnel research was done, finally backed up with some smart mathematics, which lead to the development of computational fluid dynamics programs (CFD).

For initial work, well established data sources like ESDU are used, and using known data of like geometries.