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the way I understand it: Fin's lift is generated when water is accelerated out of the template's foil, or simply put, when water rushes goin from a big area to a smaller one.
For the board itself, I guess the same principle applies.
-------------------- Cabo!
Post Extras:
laidback
Miki Dora status
Reged: 02/09/07
Posts: 4236
Loc: NOC
I guess the toed in fins generate some sort of drag, but I wont get into that cause the wave and gravity are generating most of our speed... unlike an airplane that uses thrust to create it.
Quote: From fins? from template? from bottom contours? from increased AoA? from quads in highline? what is it exactly?
Lift is turning of the flow.
It is simple. Anytime the flow is curved, lift is created. From fins, or from the hull. Regardless if the flow is moving or the board is moving, or both.... lift is created.
moving through water alone creates drag, water wants to hold on to the surface and youre either planning or displacing, as speed increases more water has to flow on the surface of the board and fins, more water means more drag... I think.
Quote: moving through water alone creates drag, water wants to hold on to the surface and youre either planning or displacing, as speed increases more water has to flow on the surface of the board and fins, more water means more drag... I think.
INSIDE: A sophisticated hydrodynamic foil consisting of a convex outside face, a rounded leading edge and a concaved inside face. Inside foil increases the efficiency of water flow over the surface of the fin adding lift and reducing drag. The result is a fin with more options through increased hold and speed.
INSIDE: A sophisticated hydrodynamic foil consisting of a convex outside face, a rounded leading edge and a concaved inside face. Inside foil increases the efficiency of water flow over the surface of the fin adding lift and reducing drag. The result is a fin with more options through increased hold and speed.
YEAAAAAAAHHHHHHPPP!
Also hijacked from another major fin manufacturer.
"Our foils are complete cross-sections (not just a concave inner surface) designed to promote the natural flow of water and therefore the water attachment to the surface of the fin. We designed our foils after experimenting with our library of thousands of combinations of NACA foils to determine what works well for different surfing applications. The benefit of our Foil Technology is how we apply different amounts of lift by controlling the pressure differential created between the outside surface and the inner surface of the fin. This differential creates lift (Drive during bottom turns) as the fin gets pushed from the high pressure on the inner surface towards the low pressure outer surface. Creating the pressure difference without inefficiency (Drag) is achieved with careful 3D design of the curves of the foil and years of experimentation to maximize clean non - turbulent water flow. The result is less drag with more lift, which you will notice in your surfing. Different surfing conditions as well as style and personal preference determine which foil you will like best. This is why we use different foils for each type of surfing: tow, paddle gun, fast waves, slow waves."
I'll try to keep it simple and not ramble. The lift generated by the foil (the side of the fin) holds the fin and rail in the water. Most of the lift that you feel from a fin is from the leading edge running into the water as you surf. More vertical fins have more lift but have abrupt pivots. More raked fin has less lift but more drive and wider turning arcs. Thicker foil also gives lift but increases drag at high speeds.
We learned a lot of this from windsurfing. When you are windsurfing you have a lot of time to feel and study the differences.
The main thing that you are trying to do with board and fin design is decrease drag which increase lift. Too much lift and your rail has trouble staying in the water. Always a balance.
-------------------- Shawd DeWitt
Rainbow Fin Co Inc
info@rainbowfins.com p 831-728-2998
Post Extras:
Havoc
Tom Curren status
Reged: 09/10/07
Posts: 10001
Loc: The OC Life
Quote: I'll try to keep it simple and not ramble. The lift generated by the foil (the side of the fin) holds the fin and rail in the water. Most of the lift that you feel from a fin is from the leading edge running into the water as you surf. More vertical fins have more lift but have abrupt pivots. More raked fin has less lift but more drive and wider turning arcs. Thicker foil also gives lift but increases drag at high speeds.
We learned a lot of this from windsurfing. When you are windsurfing you have a lot of time to feel and study the differences.
The main thing that you are trying to do with board and fin design is decrease drag which increase lift. Too much lift and your rail has trouble staying in the water. Always a balance.
sweet! thanks shawd!
-------------------- "motions of rippage is initated by the hind leg"-Northern_Shores
"Lemme know. I got endson gas"-20W
Post Extras:
WarrenC
Michael Peterson status
Reged: 11/30/08
Posts: 2763
Quote: I'll try to keep it simple and not ramble. The lift generated by the foil (the side of the fin) holds the fin and rail in the water. Most of the lift that you feel from a fin is from the leading edge running into the water as you surf. More vertical fins have more lift but have abrupt pivots. More raked fin has less lift but more drive and wider turning arcs. Thicker foil also gives lift but increases drag at high speeds.
We learned a lot of this from windsurfing. When you are windsurfing you have a lot of time to feel and study the differences.
The main thing that you are trying to do with board and fin design is decrease drag which increase lift. Too much lift and your rail has trouble staying in the water. Always a balance.
sweet! thanks shawd!
nice to see you post Shawd, wish you'd post more often, always enjoy your posts and learning from what you have to say
-------------------- What fin sets work well with this board.
When flying down the line and hopping up on the lip for that big long lip glide. Is it the curved side of the fin holding you up there or the planing of the fins surface area and template shape ?
absolutly greg, you´re right. i think airplanes are a good example. wings are very diferent in surface area and foil for diferent purpose. i just think we can´t look at one without keeping an eye on the other.
what you think? to me it looks like he is even going one step further with the reduzed area on the tip. X-wave, X-twin
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