三维非等温聚合物熔体充填问题的相场方法  

Non-isothermal Polymer Filling Process via Phase Field Method in Three Dimensions

作　　者：高普阳 GAO Puyang(School of Science,Chang'an University,Xi'an,Shaanxi 710064 China)

机构地区：[1]长安大学理学院,陕西西安710064

出　　处：《计算物理》2023年第6期689-698,共10页Chinese Journal of Computational Physics

基　　金：国家自然科学基金(11901051、11971075);陕西省科协青年人才托举计划项目(20220504);长安大学中央高校基本科研业务费项目(300102122107)资助。

摘　　要：针对三维非等温聚合物充填问题,基于相场方法进行数值模拟研究。依据相场模型参数可以将整个区域内的流场控制方程写为统一形式,并采用Cahn-Hilliard方程追踪牛顿和非牛顿流体之间的运动界面。此外,Cross-WLF模型用来描述非等温条件下,聚合物熔体粘度的变化规律。依据特征线分裂格式对于统一的Navier-Stokes方程进行解耦,并采用FEM和SUPG方法分别求解椭圆型、对流-扩散型子方程。以长方体薄壁型腔及带有圆柱嵌件的长方体薄壁型腔为例,实现三维非等温聚合物熔体的充填过程,并分析注射速度及浇口尺寸对于充填过程的影响。数值结果与实验结果吻合较好,并且能够保证非牛顿流体较好的质量守恒性。We investigate the non-isothermal non-Newtonian filling process according to the phase field method in three dimensions.The moving interface between the Newtonian and non-Newtonian fluid is captured by the Cahn-Hilliard equation.Based on phase field parameters,the governing equations of theflow field could be wrtten in a unified form.After that,the Navier-Stokes equations are split into several sub-equations and the FEM and SUPG wll be used to handle the appropriate equations.The variation of the viscosity of the polymer melt is described via the Cross-WLF model.The thin wall rectangular cavities with and without obstacles are considered to illustrate the convergence,robustness and accuracy of the numerical algorithm.The influences of the inlet velocity and the size of the injection gate on the filling process are analyzed.The numerical results agree well with the experimental data and also exhibit good mass conservation properties.

关 键 词：非等温 充填过程 Cross-WLF模型 相场方法 有限元 

分 类 号：O242.1[理学—计算数学]