This paper presents the numerical analysis of the Nonlinear Subgrid Scale (NSGS) model for approximating singularly perturbed transport models. The NSGS is a free parameter subgrid stabilizing method that introduces an extra stability only onto the subgrid scales. This new feature comes from the local control yielded by decomposing the velocity field into the resolved and unresolved scales. Suc...

Purely dissipative eddy–viscosity subgrid models have proven very successful in large–eddy simulations (LES) at moderate resolution. Simulations at coarse resolutions where the underlying assumption of small–scale universality is not valid, warrant more advanced models. However, non-eddy viscosity models are often unstable due to the lack of sufficient dissipation. This paper proposes a simple ...

The large eddy simulation (LES) equations of turbulent ows are formally derived by applying a low-pass lter to the Navier-Stokes equations. As a result the subgrid-scale (SGS) stress tensor strongly depends on the assumed lter shape, which causes an SGS model to be lter dependent. In particular, depending on the choice of the lter the corresponding SGS model should satisfy very diierent require...

In this paper we propose and study a subgrid model for linear convection-diiusion-reaction problems with fractal rough coeecients. The subgrid model is based on extrapolation of a modeling residual from coarser scales using a computed solution on a nest scale as reference. We show in experiments that a solution with subgrid model on a scale h in most cases corresponds to a solution without subg...

1. Motivation and objectives In the foreseeable future, Direct Numerical Simulation (DNS), a technique in which all flow scales are resolved, will remain computationally unaffordable for turbulent reacting flows at technically relevant high Reynolds numbers Thus, Large Eddy Simulation (LES), which resolves only the large scale motion of the flow while modeling the contribution of the small (sub...

Stefan Heinz∗ and Harish Gopalan 1000 East University Avenue, Department of Mathematics, University of Wyoming, Laramie 82071, USA Abstract The existence of many different dynamic large eddy simulation (LES) methods leads to questions about the theoretical foundation of dynamic LES methods. It was shown recently that the use of stochastic analysis enables a theoretically well based systematic d...