NUMERICAL-ANALYSIS FOR POLYMER MELT FLOW IN INJECTION-MOLDING

A numerical method using a finite element approach is proposed to anal yze the unsteady three-dimensional flow of power-law fluids with movin g free surfaces. Based on the fractional step method and Rational Rung e-Kutta(RRK) method for mass and momentum equations, this method is a semi-explicit scheme with unconditional numerical stability for pseudo plastic fluids. The transfer equation for the volume fraction of molte n polymer is solved to calculate the moving free surface. The energy e quation is divided into the transfer and diffusion equations. These eq uations are solved by a modified characteristic curve method and the R RK method, respectively. The calculation results are obtained by the p resent method for two box-shaped cavity flows. These are compared with the experimental results using a short-shot injection technique. Expe rimental and computational findings agree within 5% regarding location of the meltfronts.