An Adaptive Mesh Rezoning for FSI Problems

In the problems of fluid-structure interaction (FSI) the mesh updating scheme plays a key role. We have developed an adaptive mesh rezoning technique which is applicable to the three-dimensional FSI problems. In order to prevent the inversion of elements in the mesh and to maintain a well-conditioned shape for successive time-step calculations, we introduce constrained conditions of dilatational strain in the least-square form as well as the gradient of displacement vectors, in relatively small elements. By the present mesh rezoning technique, even under the large deformation of boundaries concerned, we can reduce the use of the process of mesh generation and switching of nodal values at the interboundary of time slabs. These steps require rather significant CPU time and induced projection errors of nodal values from the previous mesh to the current one. The case of collapsing tube problems shows the remarkable potential of our method. The present method is entirely general in that it can be applied to structured and unstructured meshes, effectively.