Passive Yaw Damping of a Teetered Rotor Versus delta-3 Angle Values

摘要

A series of preliminary experiments has been completed to delineate the combinations of passive cyclic pitching conditions which are favorable. The conditions surveyed have included: upwind and downwind modes of operation; a wide range of delta sub 3 angle settings, from +70 exp 0 to -70 exp 0 ; rotor angular speeds from 300 to 750 rpm and the resulting ranges of teeter angles and yaw rates. Negative settings of the delta sub 3 angle and large positive delta sub 3 values caused pronounced instabilities for both upwind and downwind modes. With delta sub 3 angle settings from 0 exp 0 to 45 exp 0 the teetered rotor in the downwind mode ran at a continuous yaw angle to the free stream wind. Midrange delta sub 3 angle values for an upwind, tailvane stabilized, rotor were favorable. (ERA citation 09:019970)