I am want to find some airfoil with high lift/drag ratio. Can any one tell me where I can try to find them with aerodynamic data too. Thanks

Ahlo

Check the classic work:

Theory of Wing Sections; Ira H. Abbot and Albert von Doenhoff (spell?) published by Dover.

Another good one is:

Aerofoil Sections by Friedrich W. Reigels, Butterworth pub.

-Jay.

What kind of consideration need to be take in choosing an airfoil in different application? Such as airplane design, propeller blade of helicopter design, wind turbine design as well as fan design?

Thanks in advance

AHLO

You don't do it that way. You design the airfoil shape ( geometry) to satisfy the requirement. For the wing, it produces lift due to pressure difference between the lower and the upper surface ( which is directly related to the geometry of the airfoil). But when the lift coefficient of the airfoil is high , you need to consider the structure aspect of the design (wing loading). The other important aspect is the lift VS angle of attack. At high angle of attack, the flow on the upper surface of the airfoil will separate and the lift diminish ( the aircraft will stall and crash ). At high speed ( for subsonic transport ) you also like to delay the formation of shock at the transonic speed so that you can reduce the drag. This requires special type of airfoil geometry. For the turbine application, the requirement is similar . But because of the rotating motion, the design must base on the so-called velocity triangles to take into consideration of the relative motion. The lift in this case is called the loading which is translated into the torque acting on the turbine shaft to produce work. For the compressor, it's the other way around.

You can also obtain the information from the following well-known resources: (1) NACA Reports and (2) Aeronautical Research Council Reports & Memoranda.

Ketut Utama

Try looking at UIUC Airfoil Data Site

http://amber.aae.uiuc.edu/~m-selig/ads.html

Don Hawken WWW home page http://www2.magmacom.com/~dhawken (last updated on December 1, 1998, demo CFD software)