Aerodynamic characteristics and dual load suppression/trim maintenance method of variable trailing-edge camber rotor

To investigate the unsteady aerodynamic characteristics of rotor with Variable Trailing-Edge Camber (VTEC), an unsteady rotor flowfield simulation method is established based on the URANS equation by introducing a deformable moving-embedded grid method. The influence mechanisms of variable-camber amplitude A_m, frequency k, and phase φ₀ on the unsteady aerodynamic characteristics of rotor are analyzed thoroughly, and whereby a VTEC optimization method is proposed through cross-iteration of variable-camber parameters to achieve the dual objectives of hub load suppression and trim maintenance. The numerical experiments indicate that the k = 3 harmonic plays a dominant role in controlling the fluctuation of vertical hub load, which corresponds to the three-bladed rotor. The feasibility of dual load suppression/trim maintenance of VTEC is demonstrated, in which the fluctuation amplitudes of hub loads increments exhibit quasi-linear relationships with A_m for k = 0 - 4 and the fluctuation phase of vertical hub load variation shifts synchronously with the adjustment of φ₀ for k = 2 - 4. The results demonstrate that the proposed load suppression method can effectively decrease the fundamental 3/rev vertical hub load and simultaneously maintain the rotor trim state.