论文标题
高保真流体结构通过径向基础函数网状壁的相互作用移动墙的适应:应用于主动脉瓣的工作流程
High fidelity fluid-structure interaction by radial basis functions mesh adaption of moving walls: a workflow applied to an aortic valve
论文作者
论文摘要
流体结构相互作用(FSI)可以通过非线性有限元模型(FEM)进行研究,该模型适用于捕获与流体相互作用的结构部分的大偏转以及计算流体动力学(CFD)。高保真模拟是使用结构和流体计算网格的良好空间分辨率获得的。一个关键的使得结构求解器和流体之间可以正确交换信息的是在湿表面上的界面的管理,该界面通常是不匹配的。一类应用程序,也称为单向FSI问题,涉及墙壁的复杂运动,该墙壁被称为FEM的测量或计算,并且必须在瞬时CFD解决方案期间在边界上施加。根据其边界的不断发展的形状,需要对CFD模型的整个计算网格进行适应时间的有效方法。一种非常完善的方法包括通过添加和去除细胞以适合移动壁的演化来再生网格的连续更新。在本文中,提出了一种基于径向基础函数(RBF)网格变形的创新方法,从而保留了相同的网格拓扑结构,适合于形状的连续更新。提出的方法是在一组给定的密钥配置的集合中精确的,并且依赖于密钥帧之间的形状混合时间插值。使用新框架进行了对聚合物假心脏瓣膜(P-PHV)的复杂运动的研究,并将其视为基于重新安排的已建立方法的参考。
Fluid-Structure Interaction (FSI) can be investigated by means of non-linear Finite Element Models (FEM), suitable to capture large deflections of structural parts interacting with fluids, and Computational Fluid Dynamics (CFD). High fidelity simulations are obtained using the fine spatial resolution of both the structural and fluid computational grids. A key enabler to have a proper exchange of information between the structural solver and the fluid one is the management of the interface at wetted surfaces where the grids are usually non matching. A class of applications, known also as one-way FSI problems, involves a complex movement of the walls that is known in advance as measured or as computed by FEM, and that has to be imposed at the boundaries during a transient CFD solution. Effective methods for the time marching adaption of the whole computational grid of the CFD model according to the evolving shape of its boundaries are required. A very well established approach consists of a continuum update of the mesh that is regenerated by adding and removing cells to fit the evolution of the moving walls. In this paper, an innovative method based on Radial Basis Functions (RBF) mesh morphing is proposed, allowing the retention of the same mesh topology suitable for a continuum update of the shape. The proposed method is exact at a set of given key configurations and relies on shape blending time interpolation between key frames. The study of the complex motion of a Polymeric-Prosthetic Heart Valve (P-PHV) is presented using the new framework and considering as a reference the established approach based on remeshing.