Numerical Methods for the Optimization of Nonlinear Residual-Based Sungrid-Scale Models Using the Variational Germano Identity

The Variational Germano Identity [1, 2] is used to optimize the coefficients of residual-based subgrid-scale models that arise from the application of a Variational Multiscale Method [3, 4]. It is demonstrated that numerical iterative methods can be used to solve the Germano relations to obtain values for the parameters of subgrid-scale models...

On the required Reynolds-number dependence of variational multi-scale Smagorinsky models

A theoretical analysis is presented on the dependence of the standard and variational multi-scale Smagorinsky models on the proximity of the LES filter width Delta to the integral length scale of turbulence L on the one hand, and to the Kolmogorov scale eta on the other hand. Moreover modifications of the models are formulated, which respond...