Identifying Weaknesses in Eddy-Viscosity Models for Predicting Film Cooling via Large-Eddy Simulations

Wall-layer Models for Large-eddy Simulations

■ Abstract Because the cost of large-eddy simulations (LES) of wall-bounded flows that resolve all the important eddies depends strongly on the Reynolds number, methods to bypass the wall layer are required to perform high-Reynolds-number LES at a reasonable cost. In this paper the available methodologies are reviewed, and their ranges of applicability are highlighted. Various unresolved issues...

Comparison of Four Eddy-viscosity Sgs Models in Large-eddy Simulation of Flows over Rough Walls

Large Eddy Simulation (LES) has become an increasingly attractive option for turbulence modeling due to the rise in computing power and the improvement in sub-grid scale (SGS) parameterizations. This study tests the improvements in simulations of wall-bounded flows over heterogeneous surfaces attained by the implementation of three improvements in the eddy-viscosity SGS closure: the dynamic mod...

Large Eddy Simulations using oodlesDST

The oodlesDST code is based on OpenFOAM software and performs Large Eddy Simulations of turbulent fluid flows. The code contains a number of specialized subgrid scale turbulence models and wall models. This report describes these models in sufficient detail to allow a new user of the code to make informed decisions regarding the use of these models for particular applications. An overview of th...

A dynamic global-coefficient subgrid-scale eddy-viscosity model for large-eddy simulation in complex geometries

Time filtering in large eddy simulations

An explicit time filter is applied to the Navier-Stokes equation prior to a space filter. The time filter is supposed to be smooth, and an exact expansion depending on the time derivatives of the velocity is derived for the associated stress tensor. On the contrary, the effect of the space filter is treated as usual and an eddy viscosity model is introduced in the LES equation. The total stress...