Abstract:The establishment of a perfect theory for the propeller flow field has been a hard job up to now. Firstly, the propeller flow field has many complicated characters such as the entire rotation, the unsteady and nonlinear characters, the 3-D effects, the interference between the vortex and the propeller, and so on. Second, the structure of the flow field hasn’t been well known. In this paper, the aerodynamic performance of the instantaneous propeller flow field was studied. The detailed flow field structures and the evolution of the aerodynamic forces were drawn. The characters of the flow field and its effects on lift and moment were analyzed.