ALE formulation for fluid–structure interaction problems

Abstract

Arbitrary Lagrangian Eulerian (ALE) finite element methods gain interest for the capability to control mesh geometry independently from material geometry. In fluid–structure interaction problems, where the fluid mesh near the structure undergoes large deformations and becomes unacceptably distorded, which drive the time step to a very small value for explicit calculations, the ALE methods or rezoning are used to create a new undistorted mesh for the fluid domain, which allows the calculations to continue. The mathematical basis of the ALE and rezoning algorithms is simple, but their implementation is complicated due to the tedious geometrical calculations associated with handling an arbitrary mesh. In this paper we apply the ALE concept to fluid–structure interaction problems. We will explain the underlying ideas of the method and a possible way to control the distortion of the mesh is given. Results of an academic as well as an industrial problem are presented.