An efficient semi-coarsening multigrid method for variable diffusion problems in cylindrical coordinates (Q881501)

The authors present an efficient mulgrid (MG) algorithm for solving the three-dimensional variable coefficient diffusion equation in cylindrical coordinates. The multigrid V-cycle combines a semi-coarsening in azimuthal direction with the red-black Gauss-Seidel plane (radial-axial plane) relaxation. On each plane relaxation, the authors futher semi-coarsen the axial direction with red-black line relaxation in the radial direction. They also prove the convergence of two-level MG with plane Jacobi relaxation. Numerical results show that the present multigrid method indeed is scalable with the mesh size.