注水参数对水辅助注射成型充填过程影响的数值模拟

建立水辅助注射成型二维、瞬态、非定常流动模型，采用黏度幂律模型，在k ω湍流模型下，充分考虑注射水的湍流特性以及熔体前沿的喷注效应，采用有限体积法（VOF）对充填过程中的注水速度、注水温度和注水延迟时间等注水控制参数的影响进行数值模拟。结果表明，注水速度的增加会增加水在熔体中的穿透长度，并且会减小残余壁厚；注水温度对水的穿透长度和残余壁厚的影响均不显著；随着注水延迟时间的增长，水的穿透长度和残余壁厚均有增加的趋势。

Numerical Simulation of Effect of Water Injection Parameters on Water assisted Injection Molding Filling Process

In order to investigate water assisted injection molding process numerically, a two dimension, transient, k ω turbulence flow model was formulated. Volume of Fluid (VOF) method was used to trace the moving interfaces. The influence of water injection speed, water temperature, and water injection delay time on water penetration was studied by numerical simulation using power law viscosity for the melt. The simulation showed that increasing water injection speed increased the water penetration length and reduced the residual wall thickness. Water temperature had little influence on the water penetration length and residual wall thickness. Increasing water injection delay time increased both water penetration length and residual wall thickness.