A numerical analytical methodology was developed for aerodynamic characteristics analysis of helicopter rotor by coupling a high-efficiency trim strategy and the computational fluid dynamics（CFD) technology. Firstly

using the CFD solver to calculate the Jacobin matrix and rotor flowfield

an analytical methodology with direct trim method was established. Then

by employing the “delta method”

the computation of Jacobin matrix was simplified and a delta trim method was developed such that the calculation time of rotor performances was significantly decreased. For the calculation of rotor flowfield

the Navier-Stokes equation was selected as the governing equation

and a second-order upwind scheme

i.e. Roe scheme

was used for spatial discretization. Implicit lower-upper symmetric Gauss-Seidel (LU-SGS) scheme was adopted for time marching

and the Baldwin-Lomax （B-L） model was selected as the turbulence model. The computation efficiency and accuracy of the “delta” trim method was compared with that of the direct trim method by numerical calculations based on experimental states of “AH-1G” and “Helishape 7A” rotors. In addition

effects of the background grid quantity on rotor trimming were also analyzed. It is shown that

compared with the direct trim method

the delta trim method can save at least sixty percent of computing time to make the trimming procedure converged. A coarse background grid is not helpful for the capture of flowfield details

but has nearly the same accuracy as a refined background grid in the calculation of rotor control settings; furthermore

the computing efficiency of a coarse grid is higher than that of a refined grid due to the lower grid quantity.