Efficient Moving Mesh Technique Using Generalized Swapping

Three-dimensional real-life simulations are generally unsteady and involve moving geometries. Industries are currently still very far from performing such simulations on a daily basis, mainly due to the robustness of the moving mesh algorithm and their extensive computational cost. The proposed approach is a way to improve these two issues. This paper brings two new ideas. First, it demonstrates numerically that moving three-dimensional complex geometries with large displacements is feasible using only vertex displacements and mesh-connectivity changes. This is new and presents several advantages over usual techniques for which the number of vertices varies in time. Second, most of the CPU time spent to move the mesh is due to the resolution of the mesh deformation algorithm to propagate the body displacement inside the volume. Thanks to the use of advanced meshing operators to optimize the mesh, we can reduce drastically the number of such resolutions thus impacting favorably the CPU time. The efficiency of this new methodology is illustrated on numerous 3D problems involving large displacements.