Large-eddy simulation of the temporal mixing layer using the Clark model
The authors examine the filtered Navier-Stokes equations for compressible flows and demonstrate the validity of Clark model for turbulent stress tensor by using Taylor expansion. Total energy density, viscous stress tensor, etc. are defined based on filtered variables and on the top-hat filter. The turbulent stress tensor is Taylor-expanded, and only the first term in this expansion is retained. The authors show that the remainder term may be not small, so the Clark model can be used, which means that the Smagorinsky eddy-viscosity model is inserted in this term. The simulation method for the temporal mixing layer is described, and the results are presented. The authors mention that in the actual large-eddy simulation (LES) the Clark model has shortcomings: namely, if the eddy viscosity is incorporated, it is extremely dissipative in the transition regime, whereas without the eddy viscosity the LES is unstable. The nature of this instability is analyzed, and a new version of the Clark model is presented, resulting in a simulation which is both stable and considerably more accurate than the original Clark model.
scientific article; zbMATH DE number 1051329
scientific article