板类制件水辅助注射成型流动过程的数值模拟研究

Numerical Simulation for Flow Behavior of Fluids in Thin Cavity during Water-assisted Injection Molding Process

基于Hele-Shaw流动模型,采用广义牛顿流体本构方程,建立了三维薄壁制件的水辅助注射成型充填阶段的数学模型,采用黏性、可压缩非牛顿流体基本方程,建立了水辅助注射成型保压补缩阶段的数学模型。采用有限元/有限差分/控制体积法数值求解。最后对一具有梯形截面水道的薄壁平板零件的水辅助注射成型流动过程进行了模拟,模拟所得到的熔体前沿位置与前人实验结果吻合较好,浇口处压力变化、水的厚度分布及平均温度分布合理。

Based on Hele-Shaw fluid model, a numerical simulation model for the flow behavior of the fluids in thin cavity during water assisted injection molding process was built up by means of general Newtonian fluid equations for the filling stage, and the basic equations of non-Newtonian, compressible, viscous fluid for the packing stage separately. Finite element/finite difference/control volume methods were adopted to solve the mathematical model. A numerical simulation example of the flow process of WAIM for a plate with trapezoidal cross-section was carried out. The simulation results of melt front location and shape were good agreement with experimental results presented in the former literature. And simulation results of pressure variation at injection location, distribution of water thickness fraction and bulk temperature at the end of filling stage were reasonable.