COARSE-GRID CORRECTION FOR NONELLIPTIC AND SINGULAR PERTURBATION PROBLEMS

The suitability of coarse-grid correction operators for multigrid solu tion of discretized nonelliptic partial differential equations is stud ied. It is found that the requirements for the orders of intergrid tra nsfers and the order of approximation of the coarse-grid operators dif fer in an important way from the well-known ''rules'' pertaining to el liptic operators. Both Galerkin coarsening and coarsening schemes base d on the differential operator are examined, and new coarse-grid corre ction strategies are suggested in light of this analysis.