1. An implicit finite-difference algorithm for hyperbolic systems in conservation-law form
2. In this paper we have presented the derivation of a time derivative preconditioning of the Navier-Stokes equations, suitable for both variable and Constant density fluids. This preconditioning was specifically designed to reduce the condition number ofthe governingsystem of equations, thus enabling efficient solution of incompressible and variable density flows over a wide range Pulliam, T. H. and Steger, J. L. "Recent Improveof speeds. The finite-volume discretization and time- ments in Efficiency,Accuracy and Convergence for Immarching schemes used tosolvethe preconditioned sys- plicit Approximate Factorization Algorithms," AIAA tem were described. Because time-derivative precondi- Paper 85-0360, Jan. 1985. tioning destroys the time-accuracy of the system, ad u d timestepping procedure was developed and presented here for solving unsteady, time-accurate flows.