EFFICIENT LIFTING LINE METHOD FOR COMPUTING PERFORMANCE OF PROPELLER

An efficient lifting line method has been developed for computing the performance of propeller.The present method features:1.The local gradient on the mean camber surface is used as a boundary condition instead of plane boundary condition so as to make the method applicable for propellers with large camber airfoil;2.A very good approximation of the velocities induced by semi infinite helical vortex lines is obtained by a combination of direct numerical integration of the exact integrand and exact analytical integration of its enveloped functions,so that the required computing time is reduced to only about 10% of the original one;3.The effects of blade section drag and compressibility have been considered in the computation of the propeller performance comparison of analytical and experimental results for a propeller are presented.It demonstrates the validity of the computational results,when the advance ratio is not too small.