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Old 05-24-2011, 09:18 AM   #7 (permalink)
KamperBob
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Quote:
Originally Posted by NeilBlanchard View Post
I believe if the air velocity is 4X as high, then the drag does scale.
My brain struggles with this. I've read about Reynold's scaling. Here's my puzzle. Drag force is directly proportional to area and the square of velocity.


A 1/4-th scale model should have 1/16-th the area of full scale. Speed is supposed to be 4X for the scale model. That term squares to 16X which cancels the 1/16-th area term. The resulting "force" looks the same for both the full and small scale vehicles. But since the area is reduced doesn't that mean pressures would be 16X on the 1/4-th scale model by comparison?

This does not seem to compute. What am I missing?
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Last edited by KamperBob; 05-25-2011 at 10:08 AM.. Reason: Correction (16X not 4X)
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