Speculation of local aerodynamic loads on helicopter rotor blade in forward flight

Abstract

Design of rotor blade is mainly the most important consideration in helicopter industry. A sufficient input data is needed for various flight conditions that should be accounted for in rotor design process. In this paper, blade element theory is applied to helicopter rotor blade in forward flight. The main objective is to assure the fidelity of using blade element theory in helicopter rotor blade design. Blade element theory is used for calculating the average lift, thrust, power for rotary wings and the local aerodynamic loads. The local non-dimensional normal force coefficients obtained from blade element theory were compared with experimental results of the 7A rotor at five non dimensional radial positions for the high speed test point 312. The results showed the same pattern of variation along the azimuth with a considered convergence along the blade radius.