An Experimental Investigation of Rotor Harmonic Airloads Including the Effects of Rotor-Rotor Interference and Blade Flexibility

摘要

Experimental airload harmonics from the first to the tenth at various blade spanwise stations are presented for single and rear tandem rotor configurations for various rotor angles of attack, tip-speed ratios, and thrust loadings. The results include the effect of blade bending motion on airload harmonics for selected test cases. Evaluation of the experimental results indicates several general conclusions of importance with regard to vibration levels of compound helicopters, tandem helicopters, and three- and four-bladed rotors. (Author)