基于改进有限体积法的三维注塑成型充模过程数值模拟.docVIP

  基于改进有限体积法的三维注塑成型充模 过程数值模拟# 严波1，李阳2，赵朋3** 5 10 15 20 25 30 35 40 45 （1. 上海交通大学材料科学与工程学院，上海 200030； 2. 华中科技大学材料科学与工程学院，武汉 430074； 3. 浙江大学流体动力与机电系统国家重点实验室，杭州 310027） 摘要：分别根据界面两侧相邻有限体积流动剪切应力相等的原则，考虑到相邻有限体积内粘 度系数的差异，改进传统的有限体积法，推导了改进的有限体积中心速度梯度、界面速度和 速度梯度的新的离散格式和计算格式。改进的离散格式和计算格式能适用于注塑成型充模过 程中型腔内塑料熔体粘度差异较大的情形，避免因粘度的变化导致界面两侧相邻有限体积内 塑料熔体流动剪切应力的急剧变化。同理，根据界面两侧热流量相等的原则，给出了有限体 积中心温度梯度、界面温度梯度的离散格式和计算格式。改进有限体积法能有效提高数值模 拟的稳定性和计算精度。采用改进的有限体积法分别模拟了盒形件和带凹槽平板的塑料熔体 充模过程，模拟结果与实验结果和商业软件模拟结果吻合。数值算例表明改进的有限体积法 能较准确地模拟注塑成型充模过程，也可应用于粘度变化比较大的其它单一流体或多种流体 的耦合数值模拟，具有重要的理论和使用价值。 关键词：注塑成型；改进有限体积法；充模；粘度；数值模拟 中图分类号：TQ320.6 3D Simulation of Filling Stage of Plastic Injection molding Based on Improved Finite Volume Method YAN Bo1, LI Yang2, ZHAO Peng3 (1. School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030; 2. School of Materials Science and Eingeering, Huazhong University of Science and Technology, Wuhan 430074; 3. The State Key Lab of Fluid Power Transmission and Control, Zhejiang University, Hangzhou 310027) Abstract: According to the equal flow shear stress at the interface in adjacent finite volumes, the traditional finite volume method (FVM) is improved in consideration of the viscosity variation of adjacent finite volumes. The new discretization and computing formulae concerning velocity gradient at the center of finite volume, as well as velocity and its gradient at the interface are deduced for the improved FVM. The new discretization and computing formulae are apt to the situation that melt viscosity varies very quickly during the filling stage of plastic injection molding. The improved FVM can avoid steep oscillation of flow shear stress in adjacent finite volume. Similarly, according to equal heat flux at the interface in adjacent finite volumes, the new discretization and computing formulae of temperature gradient are also given when the changing of heat conductivity coefficient is taken into account. Thus the improved FVM results in numerical