Why use an asymmetric fin

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Why use an asymmetric fin?

An asymmetric fin allows the same size fin to produce more lift for roughly the same amount of drag. This directly improves the lift-to-drag ratio, making a more effective fin. See the following graphs which show a comparison between a symmetric slalom foil in black, and the same foil in red with a coefficient of lift of 0.2, making it an asymmetric.

Lift to drag comparison between two sections. The black line shows the lift-to-drag of a symmetric section. The red line shows the same foil applied to a cambered centerline, making an asymmetric section.
Lift to drag relative to angle of attack. Notice how the asymmetric section makes lift even at 0 and negative angles of attack. So typically an asymmetric fin will not crab the board sideways as much as a symmetric section.

 

 

 
 
 
Copyright © 2007 Parametrix Pty Ltd
Last modified: July 27, 2007