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Old 03-21-2011, 12:51 AM   #512 (permalink)
fidalgoman
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Quote:
Originally Posted by Smokingwheels View Post
I think they scaled the dimples up to about 2.5-3 inches across
That was the problem. Golf ball dimples don't scale up. It has everything to do with Reynolds numbers. That means how thick the air appears to the object. For example the air seems much thicker (low reynolds number) to a bee than an airliner (high Reynolds numbers). Scale of the part to the comparable air viscosity is what matters. If you want the dimples to work like they do on a golf ball you need to make them golf ball size to solve golf ball size flow problems. There is a ton of information on this subject for all to see.

Similarly it's like floating a needle on the surface of the water due to the surface tension. You can only go so far before the scaling no longer works. Water surface tension is a relatively fixed value. There is just no way that it will scale to even floating a crow bar. It just doesn't scale past a certain point. It also becomes more extreme in effect the smaller an object gets. So like surface tension, the atmospheric viscosity is a relationship with the part, scale, and speed.

At the scale of our automobiles, Aerodynamics is entirely different than it is to a golf ball. Kind of like the drag on the wheels from a gravel road is different to a skateboard than a Honda.

Last edited by fidalgoman; 03-21-2011 at 01:11 AM..
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