This paper compares the performance of seven different element agglomeration algorithms on unstructured triangular/tetrahedral meshes when used as part of a geometric multigrid. Five of these algorithms come from the literature on AMGe multigrid and mesh partitioning methods. The resulting multigrid schemes are tested matrix-free on two problems in 2D and 3D taken from radiation transport applications; one of which is in the diffusion limit. In two dimensions all coarsening algorithms result in multigrid methods which perform similarly, but in three dimensions aggressive element agglomeration performed by METIS produces the shortest runtimes and multigrid setup times.

本文比较了当用作几何多重网格的一部分时，七种不同的元素聚结算法在非结构化三角形/四面体网格上的性能。这些算法中的五种来自有关AMGe多重网格和网格划分方法的文献。最终的多重网格方案在​​辐射传输应用中针对2D和3D两个问题进行了无矩阵测试。其中之一是在扩散极限内。在两个维度上，所有粗化算法均会产生类似的多网格方法，但在三个维度上，由METIS执行的侵略性元素集聚将产生最短的运行时间和多重网格设置时间。