Quote:
Originally Posted by ChazInMT
But Again I say, this attached flow on an extreme shape is not our friend, it creates a lot of drag.
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I have to disagree with you once again. Maybe this treatise on golf balls will convince you:
"The air hits the front of the ball, creating a high pressure area, and splits around to the sides. The air however is going too fast to make the turn around the back of the ball. It separates from the surface, leaving a low pressure wake like the one a boat leaves in the water.
This combination of high pressure on the front of the ball with low pressure on the back is the main source of a ball's drag. This may seem hopeless, but it's not. Maybe you can't control the teenager, but you can put better tires on his or her car. The solution? Dimples. When the surface of the ball is covered with dimples, a thin layer of air next to the ball (aerodynamicists call it the boundary layer) becomes turbulent. Rather than flowing in smooth, continuous layers (a laminar boundary layer), it has a microscopic pattern of fluctuations and randomized flow. Here's the good part: a turbulent boundary layer has better tires. It can better follow the curvature of the ball's profile.
It travels farther around the ball before separating, which creates a much smaller wake, and much less drag. In fact, a dimpled golf ball has only about half the drag of a smooth one."
http://www.furthereducationlessontra...rodynamics.pdf