The viscous flow fields of a propeller with six blades have been numerically simulated with unsteady N-S equations based on structured sliding grids of multiple blocks. The rotational subzone containing the propeller and the stationary subzone was constructed separately based on MFR(multiple frames of reference)

proving this is an effective approach to resolve the problems involving relative rotation of the propeller. The data of the calculation and the experiment agreed very well and proved that the method had good accuracy to simulate the fluids of a propeller. Then the complicated flow fields behind the propeller with advanced ratio of 0.90 and 0.75 were analyzed

and the static and dynamic features of the propeller trailing vortex the same as the phenomenon in the test were achieved: two opposite layers were incorporated into the propeller trailing vortex. The rules influenced by the propeller on the axial velocity were obtained: the increase of the income flow velocity in the area of 45% and 70% of the radius of the blade after the propeller is larger than the area of 90% of the radius; with the decrease of the advance ratio

the axial velocity still increases

and the area of the 90% of the radius almost keep unchanged.