8 replies to this topic

[makio_a]

Please let me know someone.
In the Olympic swimming race, athlete can swim faster with rough skin surface (shark-skin) than smooth surface of swimming suit.
Golf ball have dimples on the surface because less air resistance.
Nevertheless, why the surface of F1-car is so smooth?

[VAR1016]

Originally posted by makio_a
Please let me know someone.
In the Olympic swimming race, athlete can swim faster with rough skin surface (shark-skin) than smooth surface of swimming suit.
Golf ball have dimples on the surface because less air resistance.
Nevertheless, why the surface of F1-car is so smooth?

Now you've done it!

Wait until Monza - I'll bet the Ferraris have a sharkskin finish ;)

PdeRL

[Christiaan]

Experiments performed by Darcy indicated that rough surface finishes only reduced drag in low Reynolds number flows. At the time I studied fluid mechanics my lecturer said that noone realy knew why low reynolds number flow was increased by a certain level of roughness. The major theory is that the development of eddy currents is reduced. Eddy's do not matter so much in high Reynolds number/high velocity flow because the object flows in the fluid faster than the eddies can develop.

BTW, golf balls are dimpled not to reduce drag, but increase lift by making the ball spin and generate a vortex similar to that of an aerofoil.

[desmo]

This subject has been the object of previous discussion here. Read this thread for more, or Christiaan has given the short version.

[AndreasNystrom]

Its used on airplanes anyway.

[mmmcurry]

I think I read somewhere that both Williams & McLaren tried it but the pits just got filled with dirt negating the effect.

Steve.

[confucius]

I'm sure the cost and weight has something to do with it as well. But yes, read the other thread

[Amaroo]

Originally posted by makio_a
Please let me know someone.
In the Olympic swimming race, athlete can swim faster with rough skin surface (shark-skin) than smooth surface of swimming suit.

The Shark skin principle which you have spoken about was succesfully used by Dennis Conner to win the 1987 Americas Cup. Before the final with the Australians, NASA and MIT worked out that by having a roughed hull of the boat it actually redused drag and in doing so increased the lift supplied by the winged keel and stopped the boat slipping sideway going up wind (Called Leeway). What this would do for an F1 car I have no idea

[TAB666]

I read somewhere that teams have tried dimples ( or atleast something like that ) to reduce drag. One problem was that dirt got stuck and you lost the effect after a few laps. I allso heard something about colour that gave the dimple effect .. but its was prolly heavy.
I might ofcourse be waaaay of the target.