A posteriori Variational Multiscale Methods for the 1D convection-diffusion equations

Abstract

The present work is a continuation of a paper presented by the two first authors in the proceedings of the “Computational Science for the $21^{\rm st}$ century” conference held in Tours in 1997 honouring the $60^{\rm th}$ birthday of Roland Glowinski. It is devoted to the solution of 1D convection-diffusion equations in dominant convection regime situations. In that paper, an “a posteriori” VMS filtering technique was introduced. We present an extension of this technique to nonlinear convection-diffusion equations (a traffic model), providing an efficient method for the resolution of shocks from just the Galerkin solution at targeted times. We also present a residual-based “a posteriori” VMS filtering, that provides quite accurate stable solutions, can be extended to multi-dimensional problems, and can be applied locally. We finally present some numerical tests exhibiting the high accuracy of the obtained solutions.

Keywords

• VMS methods
• dominant convection
• a posteriori filtering
• stabilisation
• convection-diffusion equation
• traffic flow equation