Node-nested multi-grid method with Delaunay coarsening

For finite-element non-structured type meshes, the non-nested multigrid algorithms require to build a sequence of independent meshes. The paper proposes an automatic way to generate the coarse meshes given the finest one. The method first eliminates a set of points from the current mesh level and then uses the Delaunay-Voronoi algorithm to triangulate the remaining set of points. The algorithm is presented and it is shown that it owns good properties with respect to multigrid algorithms. Several examples of its application to bi-dimensional meshes are presented.