Method of improving a blade so as to increase its negative stall angle of attack

摘要

A method of improving a blade and also an improved blade and a advancement propeller including the improved blade. The radius of the initial leading edge circle of each airfoil of the blade is increased, and its leading edge is moved away from a pressure side half-airfoil towards a suction side half-airfoil, thereby modifying the airfoil of each cross-section of the blade and modifying the camber of each airfoil. Consequently, the absolute value of the negative stall angle of attack of the blade is increased, thus making it possible to increase the aerodynamic performance of the blade under a negative angle of attack compared with a blade that is not modified, and without significantly degrading its aerodynamic performance under a positive angle of attack.