Development of Parallel Finite Element System for Fluid-Structure Interaction Problems by Using Eulerian Description

本研究采用欧拉描述法建立了流固耦合问题的并行有限元系统。采用欧拉描述法发展固体和流体的数值方法采用流体体积法描述固体和流体之间的界面函数。采用基于SUPG（流线迎风/Petrov Galerkin）和CIVA（体积/坐标三次插值）方法的稳定有限元法对VOF函数的平流方程进行离散化。对于固体分析，将控制方程分为两个部分；平流阶段和非平流阶段：平流阶段采用稳定有限元法，非平流阶段采用标准Galerkin有限元法。采用显式方法进行时间离散化。另一方面，流体分析采用稳定有限元法进行空间离散，时间离散采用隐式有限元法。通过与已有的实验、理论和计算结果的比较，验证了这些方法的有效性。流固耦合问题并行有限元系统的开发利用欧拉描述法建立了流固耦合问题并行有限元系统。流固耦合的数值计算方法采用弱耦合方法。采用基于域分解的并行计算方法，减少了CPU时间和计算机存储空间。设计了一种适用于非结构化网格的MPI并行实现，并在PC集群并行计算机上使用。计算结果与已有的实验、理论和计算结果吻合较好，获得了较高的并行效率。研究结果表明，该并联有限元系统是求解大变形流固耦合问题的有力工具。少

The development of parallel finite element system for fluid-structure interaction problems by using Eulerian description was performed in this research work.1.Development of numerical method for both solid and fluid by using Eulerian descriptionThe VOF(Volume of Fluid) method is employed for the description of interface function between solid and fluid. The stabilized FEM based on the SUPG (streamline upwind/Petrov Galerkin) and CIVA (cubic interpolation using volume/are coordinate) method are employed for the discretization for the advection equation of VOF function. For the solid analysis, the governing equation was divided into two ; advection phase and non-advection phase : The stabilized FEM was employed for the advection phase and the standard Galerkin FEM was employed for the non-advection phase. The explicit method was employed for the temporal discretization. On the other hand, for the fluid analysis, the stabilized FEM was employed for the spatial discretization and the impli … More cit method was employed for the temporal discretization.The vaidity and efficiency of these methods have been investigated by the comparison with existing experimental, theoretical and computational results.2.Development of parallel FEM system for fluid-structure interaction problemsA parallel FEM system for fluid-structure interaction problems was developed by using Eulerian Description. The weak coupling method was employed for the numerical method for fluid-structure interaction. The parallel computing method based on the domain decomposition method was employed in order to reduce the CPU time and computer storage required. A parallel implementation using the MPI suitable for unstructured grid was designed for the use on PC cluster parallel computer.The computational results were good agreement with the existing experimental, theoretical and computational results and the highly parallel efficiency was obtained.From the results obtained in this research work, it can be concluded that the present parallel FEM system is useful and robust tool for the fluid-structure interaction problems with large-deformation. Less