Local dynamic gradient Smagorinsky model for large-eddy simulation

Abstract

The dynamic Smagorinsky model for large-eddy simulation of turbulent flow is often applied with some kind of spatial averaging to prevent the instability of simulations. This paper demonstrates that the local model constant of the dynamic Smagorinsky model has a singularity if spatial averaging is not applied. The paper identifies the large local values arising from this singularity as a source of numerical instability and proposes an alternative dynamic model without the singularity. This local dynamic model has improved stability and provides good results in simulations of canonical turbulent flows.