Effects of condition number on preconditioning for low Mach number flows

The effects of the condition number on convergence characteristics and solution quality for the preconditioned Navier-Stokes equations are studied. A general approach to the construction of preconditioning parameters is proposed to account for the effects of the condition number on these parameters. To verify this technique, laminar flows past a circular cylinder at Reynolds numbers of 20 and 40, and laminar flows past a NACA0012 airfoil at Reynolds numbers of 2500 and 5000 are solved. It is shown that the condition number has effects on the convergence characteristics and solution qualities, and also that a condition number exists that optimizes the convergence characteristics and solution quality. (C) 2012 Elsevier Inc. All rights reserved.