Golf balls have them in order to cut down on wind resistance–less surface area, flys farther. Wouldn’t this be a good idea for cars, too? Save on gas, etc?
I’ve been wondering about this for a while, now. I realize that a slick, shiny surface might be more appealing to buyers of cars, but wouldn’t a dimpled surface be more aerodynamic? What would happen if the surface were coated with Teflon? (Yeah, I know that Teflon wouldn’t want to stick very well to the sheet-metal, but humor me here…)
My understanding is that it’s just the rear of the object that benefits from a turbulent airflow. Balls are symmetric so they are dimpled all over. Many cars are equipped with spoilers that are supposed to do the same thing - i.e. “spoil” the clean flow of air.
Golf ball dimples work because of the ball’s rotation: as the ball spins (backwards, because of the striking angle)the dimples on the bottom “grab” the air, creating a pressure differntial - the ball rises because the air pressure above it is lower. It increases “hang time” in the air.
You’d be hard pressed to design a car or a plane that could use this effect.