Quote:
Originally Posted by 2000mc
Most of the things I've seen dimples on are objects that spin, or don't really have a front. I haven't seen a dimpled helmet, but I know the last street bike helmet I bought, shoei claimed to of done work to try to neutralize changes in lift and drag depending on the direction you're looking. So even though it clearly has a front, I could see dimpling tring to minimize the effects.
Do you have examples of dimpling used on hulls?
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Dimple bottom drift boat, which is said to be super easy to handle on moving water thanks to the dimple hull design. Not saying this is proof that it works on a car, just providing an example other than a golf ball
From their website:
"Why do we love dimples? Indeed it's no accident that both a major European automaker and a power boat manufacturer have introduced dimpled bottoms or undercarriages on their most recent models. Of course, there's also the tried and true modern golf ball, the pocked surface of which has been the industry standard since Herbert Hoover held office.
As a recognized leader in the research and development of drift boat technology and as an avowed enemy of "drag" (exemplified by the unparalleled performance attained by our breakthrough tunnel hull design), we simply had to investigate the buzz behind dimples. Here's what we found: the laminar flow past a smooth surface produces more pressure and resistance than the turbulent flow past a textured or dimpled surface"
And I have found several reviews that are similar to this one:
"I found that the stopping time didn’t seem any better than a normal bottom, but once I got the boat stopped, it took very little effort to hold in place. In fact in some cases, i actually occasionally had to dig the oars into the current to get her to go downstream. I’m not sure how to describe it, but I can feel the water flowing under and past the hull better in this boat than in previous vessels."
Surf Boards had dimples in the 90's, and here is a pretty common statement I've seen made about them (granted I've only seen it talked about like 6 times). The consensus is that it didn't help speed, or handling, but made rougher water feel smoother... Like it was gliding across the top, same statement the guy made about the drift boats
"Phazer surfboards and windsurf boards came our in the early 90's, I had two of them myself. Dimples that were carved into the bottom of the boards at the rear 1/3 of the board in front of the fin(s). Bigger of course, about 1 1/2" wide by about 3" long, a pattern of about 10 or 12 of them, spread out in that area. They didn't seem to hurt the performance of the boards, but as for speeding them up? I didn't see it, or feel it. But they did seem to smooth out the ride a bit in rough water."
There's also the non-uniform surface treatments that try to replicate sharks skin. This paint from Fraunhofer-Gesellschaft in Germany:
"They first developed paint made with nanoparticles that allow it to withstand temperatures ranging from -55 to 70 degrees Celsius, intense UV radiation and the speeds of air travel.
They then determined the best way to apply the paint to airplane exteriors in a way to mimic scales was to use a stencil.
The researchers also tested the paint and application process on a ship in a ship construction testing facility, finding that the paint reduces friction by more than five percent. Over one year of use, they say, the paint would reduce a large container ship's fuel needs by 2,000 tons."
~C