三维非等温聚合物充填过程的可计算建模及数值模拟研究

The polymer filling process belongs to non-isothermal viscoelastic two-phase flow. The injection velocity, temperature and other parameters significantly effect the polymer filling process, which will relate to the appearance and performance of the final products. This project devotes to build suitable computational model, develop efficient coupled method and study the non-isothermal polymer filling process via numerical simulation, which specifically includes: (1) considering the influence of temperature for the elasticity of polymer melt to build the non-isothermal eXtend Pom-Pom(XPP) constitutive model, based on the existing isothermal XPP constitutive model; (2) propose a coupled method: utilizing the macro type method to solve the flow field governing equations, and tracking the moving interface by cell based particle method (CBPM); (3) accomplish the numerical simulation of non-isothermal polymer filling process in three dimensional complex cavities, analyze the effects of control parameters for the filling process and optimize those parameters. When building the non-isothermal constitutive model, the key problem is to introduce reasonable temperature-stress interaction term. The key problems in the computation involve the information transfer between macro method and particle method, impose the boundary conditions, the stability and efficiency of the coupled method. Through the study of this project, several vital model theory and computational problems in the numerical simulation of non-isothermal polymer filling process will be settled.

聚合物充填过程属于典型的非等温粘弹性两相流动，注射速度以及温度场等因素对于该过程都会产生显著的影响，从而直接关系到最终制品的外观和性能。本项目致力于建立合理的计算模型并发展有效的耦合算法，数值模拟研究非等温聚合物充填过程，具体包括：(1)基于等温条件下的eXtend Pom-Pom(XPP)本构模型，考虑温度对于熔体弹性的影响，建立非等温XPP本构模型；(2)建立宏观方法求解流场方程、基于网格单元的粒子方法追踪运动前沿界面的耦合算法；(3)实现复杂型腔内三维情形下非等温聚合物充填过程的数值模拟，研究各控制参数对于该过程的影响机理，并对其进行优化。其中，非等温本构模型建立的关键问题是引入合理的温度-应力作用项；计算方面的关键问题是宏观方法和粒子方法之间信息的传递、边界条件的施加、耦合求解格式的稳定性及效率等。通过本项目的研究，将解决数值模拟非等温充填过程的一些关键模型理论及计算问题。