DOI: 10.1615/ICHMT.2006.TurbulHeatMassTransf
ISBN Print: 978-1-56700-229-4
ISSN: 2377-2816
A modified wall-damping function for Large Eddy Simulation employing Kolmogorov velocity scale
ABSTRACT
A new wall-damping function, based on Kolmogorov velocity scale, for large eddy simulation (LES) is investigated. To calculate Kolmogorov velocity scale, the dissipation rate of turbulent energy, ε, is needed. In some studies, the dissipation rate of the subgrid-scale (SGS) turbulent energy, εSGS, is used instead of ε. However, since εSGS contains only the components in the scale smaller than the grid-filter width, the damping effect depends on the grid resolution employed and generally becomes inappropriate. To overcome this problem, we propose a method for estimating ε from εSGS. The revised wall-damping function is tested in channel flows and a backward-facing step flow. The results show that it gives proper near-wall damping effect in all test cases which cover a considerably wide range of grid resolution. It is also confirmed to be effective both in one-equation and 0-equation SGS models.