A CFD method with high precision was adopted to investigate the characteristics of three-dimensional (3D) effects of flow on rotor dynamic stall. The Helishape 7AD rotor was taken as example

and the influences of three-dimensional effects on rotor unsteady aerodynamic characteristics were researched. The effects of inflow Mach number on dynamic stall of rotor airfoil were investigated. On these bases

characteristics of unsteady vortex and induced flow on rotor dynamic separation were numerically analyzed

and the comparisons with the 2D states indicated that due to the effects of the rotation of blade and axial-induced velocity

the formation

convection and shedding of dynamic stall vortex on rotor blade section delayed compared with the 2D state of airfoil

and the intensity of vortex was weaker. As blade section was closer to root of rotor

differences for characteristics of dynamic stall between rotor blade section and the 2D state rotor airfoil were more obvious.