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Surfboard Shapers
A surfboard is a narrow plank used in surfing. Surfboards are relatively light, but are strong enough to support an individual standing on them while riding an ocean wave. They were invented in ancient Hawaii, where they were known as ''papa he'e nalu'' in the Hawaiian language, and were usually made of wood from local trees, such as koa. They were often over in length and extremely heavy. Major advances over the years include the addition of one or more fins (skegs) on the bottom rear of the board to improve directional stability, and numerous improvements in materials and shape. Modern surfboards are made of polyurethane or polystyrene foam covered with layers of fiberglass cloth, and polyester or epoxy resin. The result is a light and strong surfboard that is buoyant and maneuverable. Recent developments in surfboard technology have included the use of carbon fiber and kevlar composites, as well as experimentation in biodegradable and ecologically friendly resins made from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wing Configuration
The wing configuration of a fixed-wing aircraft (including both glider (aircraft), gliders and powered aeroplanes) is its arrangement of lifting and related surfaces. Aircraft designs are often classified by their wing configuration. For example, the Supermarine Spitfire is a conventional low wing cantilever monoplane of straight elliptical planform with moderate aspect ratio and slight dihedral. Many variations have been tried. Sometimes the distinction between them is blurred, for example the wings of many modern combat aircraft may be described either as cropped compound deltas with (forwards or backwards) swept trailing edge, or as sharply tapered swept wings with large leading edge root extensions (or LERX). Some are therefore duplicated here under more than one heading. This is particularly so for variable geometry and combined (closed) wing types. Most of the configurations described here have flown (if only very briefly) on full-size aircraft. A few theoretical designs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winglets
Wingtip devices are intended to improve the efficiency of fixed-wing aircraft by reducing drag. Although there are several types of wing tip devices which function in different manners, their intended effect is always to reduce an aircraft's drag by partial recovery of the tip vortex energy. Wingtip devices can also improve aircraft handling characteristics and enhance safety for following aircraft. Such devices increase the effective aspect ratio of a wing without greatly increasing the wingspan. Extending the span would lower lift-induced drag, but would increase parasitic drag and would require boosting the strength and weight of the wing. At some point, there is no net benefit from further increased span. There may also be operational considerations that limit the allowable wingspan (e.g., available width at airport gates). Wingtip devices help prevent the flow around the wingtip of higher pressure air under the wing flowing to the lower pressure surface on top at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winged Keel
The winged keel is a sailboat keel layout first fitted on the 12-metre class yacht ''Australia II'', 1983 America's Cup winner. Design This layout was adopted by Ben Lexcen, designer of ''Australia II''. Although Ben Lexcen "had tried the winged keel idea before",Bruce Stannard, ''Ben lexcen, the man, the keel and the cup'', Faber and Faber, 1984, there is conjecture that it was computed and designed by a Dutch aerodynamicist at the Wageningen towing tank (Netherlands Ship Model Bassin). Wings The lateral wings of Australia II are of moderate aspect ratio, forming a nearly horizontal foil, the "wing", at the bottom to provide additional effective span, in the same way as the winglets on an aircraft. Each wing acts as a winglet, effectively increasing the keel aspect ratio therefore reducing the lift-induced drag. Because the yacht is heeled over when sailing upwind, the leeward foil attains more draft, which reduces the loss of efficiency that always occurs under heel. The wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ben Lexcen
Benjamin Lexcen AM (born Robert Clyde Miller, 19 March 1936 – 1 May 1988) was an Australian yachtsman and marine architect. He is famous for the winged keel design applied to ''Australia II'' which, in 1983, became the first non-American yacht to win the prestigious America's Cup in 132 years. Early life Born in the small town of Boggabri, New South Wales on 19 March 1936. After his parents, labourer Edward William Miller and Ethel Doreen, née Green abandoned him as a child he stayed briefly at Boys' Town, Engadine, before going to his grandfather at Newcastle. He left school at age 14 to pursue a locomotive mechanic's apprenticeship but soon found his attention turning to sailboats. At 16, he designed his first sailboat ''The Comet'' with his friend William Bennett in Hamilton, NSW, and began to make a name for himself in local competition. Miller did his sailmaking apprenticeship with Norman Wright in Queensland. Miller's designs were highly innovative. His entry, "Taipan" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunnel Fin
A tunnel fin is a type of surfboard fin used on surfboards, especially heavy longboards and longboard guns. The weight and length of these boards make it easier to control the fore and aft angle of the tunnel. As the name suggests, it is shaped like a tunnel. Tunnel fins were first used by Richard Deese and Bob Bolen (also known as the Greek) in California during the late sixties and continue to be developed by shapers today. Background The Tunnel fin is based on the principle of the annular wing with the lowest drag and highest lift fin configuration possible. It has no drag inducing fin tips, this is important as it means that rail to rail turning movements are drag-free and effortless. Tunnel fins have the ability to enhance hydrodynamics by slightly twisting the water flow into a vortex as it passes through the tunnel, preventing random turbulence in its wake. The tunnel fin has a large amount of horizontal lift utilizing the hydrofoil principle providing better lift-to- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
