Systems of Conservation Laws

Local PDF: ADA385056.pdf

AD Number: ADA385056
Subject Categories: NUMERICAL MATHEMATICS FLUID MECHANICS
Corporate Author: LOS ALAMOS NATIONAL LAB NM
Title: Systems of Conservation Laws
Personal Authors: Lax, Peter
Report Date: 19 APR 1959
Pages: 39 PAGES
Report Number: LA-2285
Contract Number: W-7405-ENG-36
Monitor Acronym: XJ
Monitor Series: XD
Descriptors: *DIFFERENCE EQUATIONS, *COMPRESSIBLE FLOW, COMPUTATIONAL FLUID DYNAMICS, SHOCK, DISCONTINUITIES, VISCOSITY, HYPERBOLIC DIFFERENTIAL EQUATIONS, COMPRESSIVE PROPERTIES, LAGRANGIAN FUNCTIONS.
Identifiers: COURANT FRIEDRICHS LEVY CONDITIONS, CONSERVATION LAWS
Abstract: In this paper a wide class of difference equations is described for approximating discontinuous time dependent solutions, with prescribed initial data, of hyperbolic systems of nonlinear conservation laws. Among these schemes we determine the best ones, i.e., those which have the smallest truncation error and in which the discontinuities are confined to a narrow band of 2-3 meshpoints. These schemes are tested for stability and are found to be stable under a mild strengthening of the Courant-Friedrichs-Levy criterion. Test calculations of one dimensional flows of compressible fluids with shocks, rarefaction waves and contact discontinuities show excellent agreement with exact solutions. In particular, when Lagrange coordinates are used, there is no smearing of interfaces. The additional terms introduced into the difference scheme for the purpose of keeping the shock transition narrow are similar to, although not identical with, the artificial viscosity terms, and the like of them introduced by Richtmyer and von Neumann and elaborated by other workers in this field.
Limitation Code: APPROVED FOR PUBLIC RELEASE
Source Code: 211350
Citation Creation Date: 03 JAN 2001