flow balance of an extrusion die for production of a u-shaped profile

the main objective of an extrusion die is flow balancing as an unbalanced flow causes a distorted product together with residual stress. in this paper a strategy is presented for flow balancing a u-shaped profile with different wall thicknesses. for this purpose, a choker bar is provided at thicker wall to locally restrict excessive flow passing through the thicker section. for optimal design some of die dimensions are considered parametric which will be variable in three levels. the analysis of flow was performed using fluent software in order to get the best combination of the parameters which produces the best balance. after the optimum design was obtained, an experimental die is manufactured. it is considered in the manufacture of the die that height of choker to be variable during extrusion for finely adjusting the balance. results demonstrate that experiments are in good agreement with simulations.