Study and Verification of Large-Scale Parallel Mesh Generation Algorithm for Centrifugal Pump

In order to reveal the details of the internal flow in a centrifugal pump, a large-scale mesh is needed. However, the mesh generated by the serial grid algorithm cannot meet the calculation requirements due to the huge amount of time. A large-scale parallel mesh generation algorithm of a centrifugal pump for high-performance computers is presented in this paper. First, a grid point set for the 3D Delaunay triangular mesh on the surface of the centrifugal pump is generated. Then, the S-H (Sutherland–Hodgman) algorithm for cropping and segmenting these grid point sets on the surface is employed. A uniform boundary mesh is generated and is divided into different subregions. In addition, in order to ensure the consistency of the interface mesh and to avoid the boundary mesh intersection overlap error, a parallel constrained Delaunay mesh generation algorithm based on region numbering is proposed, which can improve the quality and efficiency of the generated parallel mesh. Finally, the centrifugal pump is tested for verifying the parallel mesh algorithm in the Tianhe-2 supercomputer. PIV (particle image velocimetry) internal flow experiment is comparatively analyzed with the numerical simulation of large-scale mesh. The results show that the algorithm can generate 108 3D unstructured grid elements in 5 minutes, and the parallel efficiency can achieve 80%. The proposed algorithm not only ensures high grid quality with the serial grid algorithm but also accurately simulates the flow law in the centrifugal pump. The double-vortex structure which is obtained by PIV experiment is captured by the large-scale mesh.