Browsing by Author "Silvester, David J."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Fast Nonsymmetric Iterations and Preconditioning for Navier-Stokes Equations(1998-10-15) Elman, Howard C.; Silvester, David J.Discretization and linearization of the steady-state Navier-Stokes equations gives rise to a nonsymmetric indefinite linear system of equations. In this paper, we introduce preconditioning techniques for such systems with the property that the eigenvalues of the preconditioned matrices are bounded independently of the mesh size used in the discretization. We confirm and supplement these analytic results with a series of numerical experiments indicating that Krylov subspace iterative methods for nonsymmetric systems display rates of convergence that are independent of the mesh parameter. In addition, we show that preconditioning costs can be kept small by using iterative methods for some intermediate steps performed by the preconditioner. (Also cross-referenced as UMIACS-TR-94-66)Item Iterative Methods for Problems in Computational Fluid Dynamics(1998-10-15) Elman, Howard C.; Silvester, David J.; Wathen, Andrew J.We discuss iterative methods for solving the algebraic systems of equations arising from linearization and discretization of primitive variable formulations of the incompressible Navier-Stokes equations. Implicit discretization in time leads to a coupled but linear system of partial differential equations at each time step, and discretization in space then produces a series of linear algebraic systems. We give an overview of commonly used time and space discretization techniques,and we discuss a variety of algorithmic strategies for solving the resulting systems of equations.The emphasis is on preconditioning techniques, which can be combined with Krylov subspace iterative methods.In many cases the solution of subsidiary problems such as the discrete convection-diffusion equation and the discrete Stokes equations plays a crucial role. We examine iterative techniques for these problems and show how they can be integrated into effective solution algorithms for the Navier-Stokes equations. (Also cross-referenced as UMIACS-TR-96-58)