Algebraic coarse grid operators for domain decomposition based preconditioners

摘要

We investigate some domain decomposition techniques to solve large scale aerodynamics problems on unstructured grids. Where implicit time advancing scheme are used, a large sparse linear system have to be solved at each step. To obtain good scalability and CPU times, a good preconditioner is needed for the parallel iterative solution of these systems. For the widely-used Schwarz technique this can be achieved by a coarse level operator. Since many of the current coarse operators are difficult to implement on unstructured 2D and 3D meshes, we have developed a purely algebraic procedure, that requires the entries of the matrix only.