Airplanes aren't. Please let me know why.

7/7/2018 9:55:40 PM

Does a golf ball on a treadmill take off?

7/7/2018 10:00:25 PM

airplanes aren't spherical

7/7/2018 10:15:38 PM

The Reynolds numbers are a lot different. Fluids behave wildly differently at different scales. Skin texture is a thing that engineers look at all the time though, but especially at lower Reynolds numbers it makes a big difference.

[Edited on July 7, 2018 at 10:26 PM. Reason : turbulent vs laminar flow]

7/7/2018 10:25:31 PM

https://www.quora.com/Why-dont-plane-designers-put-golf-ball-dimples-on-aircrafts-to-increase-the-efficiency

7/7/2018 10:51:38 PM

if you could keep the flow laminar around the golf ball, without boundary layer separation, a smooth surface would be superior...but turbulent flow (from the dimples) is superior to laminar flow that has separated.

incidentally, some airplanes DO have the equivalent: vortex generators on the top of the wing. It costs a little efficiency, but it makes the airplane considerably harder to stall.

7/7/2018 11:43:20 PM

Do airplane dimples need to be actual golf ball sized, like a few mm wide, or should they be scaled up for the plane?

7/8/2018 1:08:57 AM

7/8/2018 1:24:04 AM

Why don't they just make golf balls out of the black box?

7/8/2018 1:33:58 AM

This brings back so many memories of MAE.

7/8/2018 9:36:15 AM

^ haha...[shudder]

^^^^ VGs aren't dimples. they're little tabs that stick up, angled in different directions. The ones I've seen range from about the size of your fingernail, up to the size of a postage stamp.

7/8/2018 10:21:52 AM

why don't golf balls have wings tho?

7/9/2018 9:24:38 AM