Spurious Behaviour of Numerically Computed Fluid Flow

Abstract
We investigate the stability to aliasing errors of numerical schemes for hydrodynamics, taking the viscous Burgers' equation as a model for systems with a term that is quadratic in the velocity. Considering wavelengths equal to three times the mesh-spacing, and arbitrary mean flow, we are able to demonstrate explicitly for common schemes (a) a sufficient criterion for stability and (b) blow-up of solutions in a finite time when (a) is violated. Singular behaviour is shown to persist at all wavelengths: studies of wavelengths up to thirty times mesh-spacing make it clear that a profile with a single region of strong convergent flow is most conducive to instability. In contrast, spectral (Galerkin) and upwind schemes are shown to be stable for all flows and periods.

This publication has 0 references indexed in Scilit: