the GN boat with a interesting bottom
14 years ago my dad and I went to irvine for the boat racers reunion i think that is what it was called? Long story short I remember a grey with black strips GN Boat the had a bottom like a golf ball but I think they may have been holes and not dimples.. What would be the purpose of this? I was watching SSers video last night and I think I saw it and remembered that bottom.
When I was building my boat I was told that I needed to make sure there was no hooks/dips, etc.. Thanks
There is a theory that the dimples/holes airate (sp?) the water and makes it less sticky............boats run faster in water with ripples than glassy water..
CC
Originally Posted by Rattle Can Lou
Again, if I came across as a v-drive snob..I apologize,
Mike
somebody tried it on an SS but it proved no advantage
Tom...lets sit down and get a beer some timeOriginally Posted by tkriley13
I wanted to do the golf ball dimple thing years ago after researching and finding out submarines got better fuel mileage because their noses and fuselages were dimpled to hold air pockets around them creating less drag...i mentioned this to a few people and their heads went 180
Dan
The technology works, most power boat racers are years behind. Multi millinon dollar yachts and sailboat racers have been using riblets for twenty five plus years. All of the America Cup sail boats and Olympic Class boats use it. The good stuff is patened and trade marked by Du Pont. I have not used it or applied it in years, but it was similar to window tint film, as far as application. Twenty years ago it was about $ 7K for enough to do a 12 meter race boat. We removed it after every race, and re applied it before each race. Watched programs on Wild World of Sports reguarding it. ( way befor ESPN was ever born )
I know the Victory Team in Dubai used it in early 90's and usually kicked everyone's ass in the offshore race boats. I would assume they probably still do.
America's cup boats and mega yachts are a different application.
They've studied dolphins and shark skin their ripples reduce drag.
Ex 9 time champ jet boat racer Ron Segni with boats that ran 105-115) tried 2 different high dollar coatings on his boat. He went slower with both, he found out the flat black paint with a light sanding worked best:
Bottom detailing/blueprinting 101:
When we detailed the bottom of my boat we did the same with flat black paint and sanding.
The films and special coatings have a lot to do with application and surface area that is in contact with the water...obviously
S CP
Last edited by Sleeper CP; 04-12-2012 at 08:48 PM.
"Dark Sarcasm"
Going fast is only half the fun ... what you make go
fast is the other half.
" A Government big enough to give you everything you want is big enough to take away everything you have"
The last few SS races I've seen the boats were out of the water about 50% of the time and as rough as the water is during a race one would think any advantage would be de minimis at best. And don't they want SS boats to "hook" when they turn? In that case slippery isn't your friend ....... I'd think(might be wrong)
S CP
"Dark Sarcasm"
Going fast is only half the fun ... what you make go
fast is the other half.
" A Government big enough to give you everything you want is big enough to take away everything you have"
Comparing the bottom of a surface riding "planing hull" and a full displacement sail boat, or ship, or fully submerged submarine, and even a golf ball that is completely surrounded by undisturbed air, is comparing apples and oranges.
The chopped surface of the water effectively acts to do basically the same thing as the surface on a golf ball. On dead smooth, "perfect reflection" water, it may very well be of some benefit. If thats your goal. On a drag boat it may be of some benefit. But the less perfect the water is, the less gain you will see. I don't think it much matters if the disturbance is on the surface of the water, or on the bottom of the boat.
LINK:GN-RACING.COM
The problem with Obama jokes is that his worshippers don't think they are funny, and the rest of us don't think they are jokes
I'm not so sure about that. The idea of a "disturbed surface" is to break laminar flow through turbulence. Once the hull pierces choppy water, at some depth, ie. lower portions of the hull, the chop will not increase turbulence. I suppose how "disturbed" the surface is will determine how well it will work at various speeds. The offshore guys create their own turbulent flow conditions by ventilating the hull with near perpendicular steps.
Michael
There is a huge difference between perpendicular steps and serpintine steps and the like, and golf ball dimples. There is a huge difference between disturbence, and trapping air.
You could increase the speed of almost any flat bottom by simply attaching the cav plate to the transom 3/4 to 1" up from the bottom. Of course thats not legal some sanctions, and may not be the best handling situation, but it will be faster. I would willing to bet a considerable increase over dimpling the cav plate.
The problem with Obama jokes is that his worshippers don't think they are funny, and the rest of us don't think they are jokes
so would it be a benefit to ball mill small grooves parallel the transom in blast plate and or the cav plate?
How about rain X on the bottom??????????
I heard some small rc boats do it, anyone on a bigger hull?
Last edited by SHAWN DAVIS; 04-13-2012 at 11:05 AM.
That's Grier's boat (a rush hull), It was at Wilkes when I worked there, very interesting pattern & depth to it, I think it still holds the kilo record.
Last edited by cakeeater ed; 04-13-2012 at 08:49 AM.
I was watching the threads in regards to speed records on water and had a big "what if." What if in the sponsons one was to put wheels recessed into the sponsons so at high speed the wheels would spin on top of the water. At speed water becomes very hard, would this create less drag, but also provide a much safer form of drag atop the water? Just curious as I know there are some engineers that frequent thses threads.
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