MacGregorSailors.com

I just read an article This One! about the aerodynamics of a whales fins, and how they are being copied to make wind turbines more efficient. Since a wing of a plane, and a sail, and a wind turbine blade all have the same characteristics, could sails be restructured to also take advantage of this interesting information. A luff with bumps on it to create a more efficient sail?



Ray

when my luff had bumps i sent her to the doctor

Wouldn't sail slide luggs do the same kind of thing already?

I got that effect once when I didn't cleat the halyard off properly and the luff fell slack. Don't recall it sailing any better.

interesting mod for a rotating mast. It should help. How much????

I know it sounds strange, but the article said that the whales could make tighter turns because of it. The science of fluids applies equally to water and air. Could a boat sail closer to the wind

Ray

well when that famous brit inventor barnes wallace,started carrying out his experiments on balls etc,he discovered that putting little dinks all over them,made them go faster and further,hence your golf ball.

for those who are not up on Mr Wallaces inventions,his fame lies mainly with the weapon syatems that he designed,"the bouncing bomb"of dambusters fames was his baby,so was the "grand slam",the latter was last used to flatten the talibans caves

James V wrote:interesting mod for a rotating mast. It should help. How much????

I am with James, this should be a simple cut and paste up for the leading edge of the rotating mast - and if it works on an think what it could do for a cat.
Ray, post a reference to the orignial story please.

dont they do something like this to the wings of a jumbo jet? they got the idea from watching geese,they use fins to break up the air and this causes less drag or something

It has been said that a boat should not have ultra smooth wetted surfaces because the water would adhere to the surface and create a suction, thus slowing the boat. Shark skin was used as an example of a rough surface for max speed. VC-17 is considered a fast race bottom and drys rough.

Since my bottom is not waxed super smooth, I resemble that remark.

Bob

Ron,

Did you click were I indicated in my original post? It says This One! (don't click this one. Click the original)That leads you directly to the article.

I keep thinking that this could work on the M's rotating mast. When it actually works If the wind turbine example is correct, then a boat with a rotating mast which is bumpy on its leading edge may point higher into the wind.

The question is, is this a mod which is possible to do without special equipment?

Ray

Sure you can build "little bumpy things" on your mast using bondo or JB Weld
but how would you check to see if it really worked without controlled conditions like a wind tunnel for testing? On the airplane wing reference (I think they are called vortex generators) they are small tabs at a 90-degree angle to the wing. You could cut 1-inch sections of aluminum angle and double back tape them to your mast. But I still don't know how to come up with a definable test to prove they work better.

Bob McLellan wrote:But I still don't know how to come up with a definable test to prove they work better.

If I think they work better that is good enough for me, I will let Mike out at Marina Del Ray worry about the testing.

Ray
Obviously if I had read the text instead of reading through the text while looking at the pictures, I would have seen the link - my duh. I am thinking that it would not be that hard to mold a positive with modeling clay and then cast it and make epoxy and fiberglass "bumps" - that way I could add in "blue light tubes" like they put on cars to dress them up - for use around the harbor and on Venitian Day. I have to think about attaching them, double faced tape would work for a while then be a mess to clean off, pop rivets but I am not big on drilling a bunch of holes in the mast, if I cast a complete wrap around except for the bolt rope slot, I would have to remove some of the hardware to slide them on but then I could run a thin flat SS strap between them to hold them in place (attach it at the existing hardware attachment points). I wonder how well they will tangle the halyards?
Ron

bscott wrote:It has been said that a boat should not have ultra smooth wetted surfaces because the water would adhere to the surface and create a suction, thus slowing the boat. Shark skin was used as an example of a rough surface for max speed. VC-17 is considered a fast race bottom and drys rough.

When I used to race small boats (Lasers, 420's, 470's, etc.), we always wet-sanded the hulls after any paint job to take off the mirror-smooth shiny finish, and we never waxed the bottoms. A super shiny smooth bottom is, in fact, slow. But it looks a lot nicer on the trailer!

- Andy

Andy26M wrote:... and we never waxed the bottoms. A super shiny smooth bottom is, in fact, slow. But it looks a lot nicer ......

- Andy

Does this even need a follow up

Back in my younger days when I was still trying to grow a mustache, I was teaching midwifery with this old Vietnamese nurse - she liked to rub my cheek and reel off some endearment. It always got a chuckle from the younger nurses in my training classes. As my language skills improved I was able to translate it as - same same baby's butt, so I guess I'm just drawn to smooth bottoms.
If Rick has ever gotten down to Mexico yet, I imagine he is admiring some smooth bottoms as well