Targeting the problem on grid generation for the CFD simulation of the unsteady aerodynamic characteristics of helicopter rotor

a highly-efficient and universal moving-embedded grid generation method was proposed. Firstly

the orthogonal and body-fitted grid around rotor blade were generated by using Poisson equations and folding approach. Then

considering the twist distribution and the complex pitching

flagging motion of rotor blade

a method for the identification of hole cells named disturbance diffraction method was established. In order to ensure the closeness of hole envelope surface

the grid refinement strategy in the hole-cutting procedure was improved. Meanwhile

based upon the determination of the hole boundary

an modified minimum distance scheme of donor element method with high efficiency and robustness was developed for searching the donor cells. On these basis

the CFD simulation method for unsteady flowfield of rotor was conducted by solving the RANS (Reynolds-averaged Navier-Stokes) equations. Finally

the aerodynamic characteristics and location of the blade tip vortex for C-T(Caradonna-Tung) and 7A (Helishape 7A) rotors were simulated by the presented method in hovering and forward flight respectively. The errors of numerical results are less than 5% according to the experiment data

and the effectiveness of CFD simulation on the unsteady aerodynamic characteristics of different rotors is demonstrated.