Study of an entropy-consistent Navier–Stokes flux

Abstract

This paper presents a study to achieve discrete entropy consistency using artificial and physical diffusion mechanisms. The study begins with the one-dimensional viscous Burgers equation, specifically looking at the shock results of entropy-conserved fluxes combined with a few choices of artificial and physical viscous diffusions. The approach is then repeated for the Navier–Stokes equations. Overall, it is demonstrated that the artificial viscosity (or entropy) terms are still needed in addition to physical viscosity to achieve entropy consistency in shock predictions, although one of the artificial terms can be dropped for high viscosity or low Reynolds number flow.