Suppression of Transmitted Harmonic Vertical and Inplane Rotor Loads by Blade Pitch Control
Final rept. Jul 1967-Nov 1968
CORNELL AERONAUTICAL LAB INC BUFFALO NY
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A method was developed to study the possibility of using higher harmonic pitch-angle inputs to eliminate the transmission of oscillatory vertical and inplane forces from a helicopter rotor to its driving shaft. The aerodynamic loads are computed by using a realistic model which represents the rotor blades by bound vorticity distributions and the wake by a mesh of segmented vortex filaments. Computed results are presented for a two-bladed teetering rotor which was approximately the same as that of the UH-1A configuration except for the assumed differences in pitch control. The required pitch-angle inputs were determined for eliminating various combinations of harmonic root shears for three flight conditions.
- Fluid Mechanics