Low Moment Airfoil Design
When the airfoil pitching moment is constrained, it is not always possible
to carry lift as far back on the airfoil as desired. Such situations arise
in the design of sections for tailless aircraft, helicopter rotor blades,
and even sails, kites, and giant pterosaurs. The airfoil shown here is a
Liebeck section designed to perform well at low Reynolds numbers with a
positive Cm0. Its performance is not bad, but it is clearly inferior in
Clmax when compared to other sections without a Cm constraint. (Clmax =
1.35 vs. 1.60 for conventional sections at Re = 500,000.)
