Variational multi-scale finite element method for the two-phase flow of polymer melt filling process
Variational multi-scale finite element method for the two-phase flow of polymer melt filling process
复制标题
聚合物熔体填充过程两相流动的变分多尺度有限元法
DOI：
10.1108/hff-07-2019-0599
复制
发表时间：
2020-01-01
影响因子：
4.2
通讯作者：
He, Ji-Huan
中科院分区：
文献类型：
--
作者：
Li, Xuejuan;He, Ji-Huan
目的本文的目的是开发一种有效的气熔两相流数值算法，并用它来模拟聚合物熔体填充过程。此外，所提出的算法可以处理移动界面和界面上未知的不连续性。设计/方法/途径代数子网格尺度-变分多尺度（ASGS-VMS）有限元方法用于求解聚合物熔体填充过程。同时，使用基于Crank-Nicolson的分割分数步算法对时间进行离散化，以减少计算时间。采用改进的水平集方法来捕获熔体前沿界面，并在空间上采用二阶Taylor-Galerkin格式和在时间上采用三阶全变分递减Runge-Kutta格式对相关方程进行离散。结果通过基准问题验证了数值方法的有效性。此外，还研究了矩形腔中的粘弹性聚合物熔体填充过程。预测了填充过程中聚合物熔体的前界面、压力场和流动引起的应力。总的来说，本文提出了一种用于聚合物注射成型的 VMS 方法。本数值方法非常适合两个自由表面问题。原创性/价值首次针对聚合物熔体填充过程的两相流进行ASGS-VMS有限元方法，并设计了一种有效的数值方法来捕获移动表面。
PurposeThe purpose of this paper is to develop an effective numerical algorithm for a gas-melt two-phase flow and use it to simulate a polymer melt filling process. Moreover, the suggested algorithm can deal with the moving interface and discontinuities of unknowns across the interface.Design/methodology/approachThe algebraic sub-grid scales-variational multi-scale (ASGS-VMS) finite element method is used to solve the polymer melt filling process. Meanwhile, the time is discretized using the Crank–Nicolson-based split fractional step algorithm to reduce the computational time. The improved level set method is used to capture the melt front interface, and the related equations are discretized by the second-order Taylor–Galerkin scheme in space and the third-order total variation diminishing Runge–Kutta scheme in time.FindingsThe numerical method is validated by the benchmark problem. Moreover, the viscoelastic polymer melt filling process is investigated in a rectangular cavity. The front interface, pressure field and flow-induced stresses of polymer melt during the filling process are predicted. Overall, this paper presents a VMS method for polymer injection molding. The present numerical method is extremely suitable for two free surface problems.Originality/valueFor the first time ever, the ASGS-VMS finite element method is performed for the two-phase flow of polymer melt filling process, and an effective numerical method is designed to catch the moving surface.