Clark Y airfoil

Source: Wikipedia, the free encyclopedia.

Clark Y is the name of a particular

chord
. The flat bottom simplifies angle measurements on propellers, and makes for easy construction of wings.

For many applications the Clark Y has been an adequate airfoil section; it gives reasonable overall performance in respect of its

stall
characteristics. The flat lower surface is not optimal from an aerodynamic perspective, and it is rarely used in modern designs.

Clark YH wingroot of a Yak-18T

The Clark YH airfoil is similar but with a reflexed (turned up) trailing edge producing a more positive pitching moment reducing the horizontal tail load required to trim an aircraft.[2][3]

Applications

Aircraft

The Lockheed Vega and Spirit of St. Louis are two of the better known aircraft using the Clark Y profile, while the Ilyushin Il-2 and Hawker Hurricane are examples of mass-produced users of the Clark YH.[4]

The Northrop Tacit Blue stealth technology demonstrator aircraft also used a Clark Y.[1] The Clark Y was chosen as its flat bottom worked well with the design goal of a low radar cross-section.

Model aircraft

The Clark Y has found favor for the construction of model aircraft, thanks to the flight performance that the section offers at medium Reynolds number airflows. Applications range from free-flight gliders through to multi-engined radio control scale models.

The Clark Y is appealing for its near-flat lower surface, which aids in the construction of wings on plans mounted on a flat construction board. Inexperienced modellers are more readily able to build model aircraft which provide a good flight performance with benign stalling characteristics.[5]

Cars

An inverted Clark Y airfoil was used on the spoilers of the Dodge Charger Daytona and Plymouth Superbird. [6]

Aircraft

Some of the better-known aircraft that use the Clark Y and YH:

References

  1. ^ a b Piccirillo, Albert, "The Clark Y Airfoil - A Historical Retrospective," SAE/AIAA paper 2000-01-5517, presented at the World Aviation Congress & Exposition, October 10, 2000, San Diego, California.
  2. ^ Lednicer, David, The Incomplete Guide to Airfoil Usage
  3. ) (History of aircraft design in USSR: 1938-1950)
  4. ^ a b c Lednicer, David, The Incomplete Guide to Airfoil Usage
  5. ^ Martin Simons, Model Aeroplane Aerodynamics, Model & Allied Publications 1978. Chapter 7 - 9, Aerofoil Sections.
  6. ^ (29 June 2005), From NASA to NASCAR, retrieved 29 April 2017

External links