An extension of lifting rotor theory to cover operation at large angles of attack and high inflow conditions

Alfred Gessow, Almer D. Crim
naca-tn-2665
Apr 1952


Analytical expressions are derived for the flapping, the thrust, the torque, and the profile-drag power of a hinged rotor that are applicable to high-speed helicopters and to certain types of convertible aircraft. The development differs from that used in the standard rotor theory in that no limitation is place on the magnitude of the blade-section inflow angles and differs also in the treatment of the reversed-velocity region. The equations may be used to calculate the performance of a lifting rotor at any angle of attack either directly or, preferably, from charts.

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