A two-dimensional numerical simulation was developed for gas-assisted extrusion through a pipe profile using the finite element method. The model was considered as viscous constitutive equations and the gas was simplified as two generalized Newtonian fluid. The effects of the gas flow on the outlet of the die shear rate field,the velocity field at the outlet of the die and die runner melt pressure at the center of the field were studied. The results show that when the gas flows into the inlet die within the...