A new dynamic subgrid-scale model for large-eddy simulation of turbulent flows

A new dynamic model for large-eddy simulations of turbulent flows that provides localized (both in time and space) determination of the model coefficients has been developed using the subgrid-scale kinetic energy equation model. In the proposed model, the dynamic modeling approach originally introduced by Germano et al. is improved to make it more generally applicable. It is shown that the shortcomings of existing dynamic models can be resolved without significant increase in complications and computational cost. Moreover, analysis shows that the localized model coefficients determined by the proposed model are Galilean-invariant and very realizable. The properties of the model have been examined by conducting large-eddy simulations of various turbulent flows such as decaying, forced, and rotating isotropic turbulence, temporally evolving mixing layers, plane Couette flows, and seperated wall-bounded flows. No further adjustment of the model was required for the simulations of these various flows. The results show good agreement with existing experimental and direct numerical simulation data.;In the present study, a new incompressible Navier-Stokes solver for time-accurate turbulence simulations has also been developed and validated by comparing large-eddy simulation predictions against experimental data.