PARALLEL MOVING UNSTRUCTURED MESHES FOR FLUID STRUCTURE INTERACTION

International audienceThis work is motivated by the success of the adaptive finite element methods in accurately simulating fluid and structure problems [5-7]. Moving rigid bodies in different fluid media is one of the main challenges that we meet when dealing with fluid structure interactions. We focus in this paper on the dynamic displacement of complex body geometries, which are discretized with unstructured meshes (triangles in 2D and tetrahedron in 3D). Moving bodies inside a meshed domain often leads to large deformations that can invalidate the mesh. In practice, a combination of mesh deformation techniques with remeshing is considered to avoid the invalidity of the mesh. However, the remeshing mechanics can penalize the performance of the whole deformation process even when it is local. We propose in this paper a fast parallel moving mesh algorithm that consists in: 1. Using a fast Inverse Distance Weight interpolation method [1] to propagate the imposed displacement on body nodes to volume nodes; 2. Extract and remesh only elements with bad quality with respect to a predefined threshold; 3. 1 and 2 are performed on a distributed mesh. We use algorithms developed in [2-5] to manage the remeshing part and we propose an efficient parallel approach to perform the interpolation part. The proposed approach is then confronted with different 2D and 3D test cases for validation and performance analysis. For example, Figure 1 shows the history mesh evolution of a 3D rotating fan and Table 1 gives some statistics on the quality of the latest deformed mesh with respect to different thresholds