Clark Y 310378 158601928 2007-09-17T23:13:53Z JetLover 4348527 moved [[AHHH!]] to [[Clark Y]] over redirect: rvv [[Image:Clark y.JPG|right|200px]] '''Clark Y''' is the name of a particular [[airfoil|aerofoil]] profile, widely used in general purpose [[aircraft]] designs, and much studied in [[aerodynamics]] over the years. The profile was designed in [[1922]] by Virginius E. Clark. The airfoil has a thickness of 11.7 percent and is flat on the lower surface from 30 percent of [[Chord (aircraft)|chord]] back. The flat bottom simplifies angle measurements on propellers, and makes for easy construction of wings on a flat surface. The [[Lockheed Vega]] is one example of the Clark Y used in practice. For many applications the Clark Y has been adequate; it gives reasonable overall performance in respect of its [[lift-to-drag ratio]], and has gentle and relatively benign [[Stall (flight)|stall]] characteristics. But the flat lower surface is sub-optimal from an aerodynamic perspective, and it is rarely used in new designs. [[Image:Clark YH.JPG|thumb|right|200px|Clark YH wingroot of a [[Yakovlev Yak-18T|Yak-18T]]]] The Clark YH airfoil was the same but with a reflexed (turned up) trailing edge producing a more positive [[pitching moment]] for improved longitudinal stability. The [[Hawker Hurricane]] used this profile. Мany [[Soviet Union|Soviet]] aircraft of the 1930s and 1940s including all of the [[World War II]] [[Yakovlev]] fighters and [[Mikoyan-Gurevich MiG-3|MiG-3]] used the Clark YH airfoil (Shavrov 1994). <br clear= "all"> ==References== * Шавров В.Б. (1994) ''История конструкций самолетов в СССР 1938-1950 гг. (3 изд.).'' Машиностроение (Shavrov V.B. (1994) ''Istoriia konstruktskii samoletov v SSSR, 1938-1950 gg. (3rd ed.).'' Mashinostroenie. ISBN 5-217-00477-0) (''History of aircraft design in USSR: 1938-1950'') [[Category:Aerodynamics]] {{Aviation-stub}}