A Multigrid Smoother for High Reynolds Number Flows∗
نویسنده
چکیده
Abstract. The linearized Navier–Stokes equations are solved in two space dimensions using a multigrid method where a semiimplicit Runge–Kutta scheme is the smoother. Explicit time-integration in the streamwise direction is combined with implicit integration in the body-normal direction. Thereby the stiffness of the equations due to the disparate scales in the boundary layer is removed. Reynolds number independent convergence is demonstrated in analysis as well as in numerical experiments.
منابع مشابه
A multigrid smoother for high Reynolds number ows
The linearized Navier-Stokes equations are solved in 2D using a multigrid method where a semi-implicit Runge-Kutta scheme is the smoother. With this smoother the stiiness of the equations due to the disparate scales in the boundary layer is removed and Reynolds number independent convergence is obtained.
متن کاملhp-Multigrid as Smoother algorithm for higher order discontinuous Galerkin discretizations of advection dominated flows: Part I. Multilevel analysis
The hp-Multigrid as Smoother algorithm (hp-MGS) for the solution of higher order accurate space–time discontinuous Galerkin discretizations of advection dominated flows is presented. This algorithm combines p-multigrid with h-multigrid at all p-levels, where the h-multigrid acts as smoother in the p-multigrid. The performance of the hp-MGS algorithm is further improved using semi-coarsening in ...
متن کاملHP-Multigrid as Smoother algorithm for higher order discontinuous Galerkin discretizations of advection dominated flows. Part II: Optimization of the Runge-Kutta smoother
Using a detailed multilevel analysis of the complete hp-Multigrid as Smoother algorithm accurate predictions are obtained of the spectral radius and operator norms of the multigrid error transformation operator. This multilevel analysis is used to optimize the coefficients in the semi-implicit Runge-Kutta smoother, such that the spectral radius of the multigrid error transformation operator is ...
متن کاملDirectional Agglomeration Multigrid Techniques for High-Reynolds Number Viscous Flows
A preconditioned directional-implicit agglomeration algorithm is developed for solving twoand three-dimensional viscous flows on highly anisotropic unstructured meshes of mixed-element types. The multigrid smoother consists of a pre-conditioned pointor line-implicit solver which operates on lines constructed in the unstructured mesh using a weighted graph algorithm. Directional coarsening or ag...
متن کاملp-Multigrid solution of high-order discontinuous Galerkin discretizations of the compressible Navier–Stokes equations
We present a p-multigrid solution algorithm for a high-order discontinuous Galerkin finite element discretization of the compressible Navier–Stokes equations. The algorithm employs an element line Jacobi smoother in which lines of elements are formed using coupling based on a p = 0 discretization of the scalar convection–diffusion equation. Fourier analysis of the two-level p-multigrid algorith...
متن کامل