Abstract: A new finite difference method with numerical simulation to solve the two-dimension coupled flow field was proposed without solving the pressure Poisson equation．The flow field of polymer melt in the single screw extruder channel under the action of vibration force field was numerically calculated‚thus obtaining the velocity and the shear stress distributions of the polymer melt in the channel at diffe-rent times．The results show that the vibration will result in a periodic variation of the velocity and shear stress in the channel‚even an instantaneous pressure backflow in the extruding direction of the channel if the disturbance coefficient of the melt is even larger．The correctness of the results mentioned above was finally proved by the curve of the shear stress distribution．

Key words: vibration force field, single screw extruder, polymer melt, finite difference method, numerical simulation