Toward efficient solution of the compressible Navier-Stokes equations

A fully implicit relaxation technique is developed to accelerate convergence of current multigrid solvers. The flux Jacobians are efficiently recomputed during iteration. The implicit operator allows increasing CFL numbers of the basic explicit scheme to O(100), and it properly addresses the stiffness in the discrete equations associated with highly stretched meshes. Compared to a well tuned, standard reference code, computation times are more than halved.