Simulation of Non-isothermal Injection Molding for a Non-Newtonian Fluid by Level Set Method

Abstract

A non-isothermal injection molding process for a non-Newtonian viscous pseudoplastic fluid is simulated. A conservative interface capturing technique and the flow field solving method are coupled to perform a dynamic simulation. The validity of the numerical method is verified by a benchmark problem. The melt interface evolution versus time is captured and the physical quantities such as temperature, velocity and pressure at each time step are obtained with corresponding analysis. A “frozen skin” layer with the thickness increasing versus time during the injection process is found. The fact that the “frozen skin” layer can be reduced by increasing the injection velocity is numerically verified. The fountain flow phenomenon near the melt interface is also captured. Moreover, comparisons with the non-isothermal Newtonian case show that the curvatures of the interface arcs and the pressure contours near the horizontal mid-line of the cavity for the non-Newtonian pseudoplastic case is larger than that for the Newtonian case. The velocity profiles are different at different positions for the non-Newtonian pseudoplastic case, while in the case of Newtonian flow the velocity profiles are parabolic and almost the same at different positions.