A DYNAMIC LOCALIZATION MODEL FOR LARGE-EDDY SIMULATION OF TURBULENT FLOWS

In a previous paper, Germane, et al. (1991) proposed a method for comp uting coefficients of subgrid-scale eddy viscosity models as a functio n of space and time. This procedure has the distinct advantage of bein g self-calibrating and requires no a priori specification of model coe fficients or the use of wall damping functions. However, the original formulation contained some mathematical inconsistencies that limited t he utility of the model. In particular, the applicability of the model was restricted to flows that are statistically homogeneous in at leas t one direction. These inconsistencies and limitations are discussed a nd a new formulation that rectifies them is proposed. The new formulat ion leads to an integral equation whose solution yields the model coef ficient as a function of position and time. The method can be applied to general inhomogeneous flows and does not suffer from the mathematic al inconsistencies inherent in the previous formulation. The model has been tested in isotropic turbulence and in the flow over a backward-f acing step.