To investigate effects of different new type blade tips on transonic characteristics of helicopter rotor

numerical analyses about the impacts of blade tips on the local flow details and aerodynamic characteristics near blade-tip were carried out. A high-precision CFD method was developed with a highly-efficient embedded grid method for the simulation of the rotor flowfield. Based on these methods

the influences of shape of blade tip on the intensity of shock wave

shock-boundary layer interference

blade tip wake and aerodynamic performance of rotor were analyzed at a transonic state respectively. The numerical results indicate that backward sweep and dihedral shape of blade tip have a smaller effect on reducing the transonic characteristics of rotor

but forward sweep and anhedral shape of blade tip can effectively reduce the transonic region

the intensity of shock wave and flow separation induced by the shock-boundary layer interference. Furthermore

sweepback blade-tip has a remarkable effect in reducing rotor torque

and straight forward sweep blade-tip can effectively reduce rotor torque (12.3% reduction of rotor torque for the case of straight forward sweep 30°) at larger rotor disc loading state

and anhedral blade-tip can effectively inhibit the blade tip vortex intensity (50% reduction of vorticity magnitude of blade-tip vortex for the case of anhedral 30°) and accelerate the dissipation of blade-tip vortex wake.