Performance of certain iterative methods in solving implicit difference schemes for 2D Navier-Stokes equations

The performance of three iterative methods, local SOR, preconditioned generalized conjugate gradient methods such as ORTHOMIN(1) and the GCG-LS method with preconditioning matrices derived by incomplete (modified and unmodified) pointwise factorizations of the matrix corresponding to implicit finite difference schemes for the 2-D Navier-Stokes equations, is compared. The relative merits of these methods in terms of CPU time, average number of iterations with respect to the Reynolds number and discretization parameters are emphasized.