A General Method for Large Eddy Simulation in Different Range of Turbulent Flows

Changping Yu

Published 2012-12-12, updated 2014-08-15Version 3

Traditional large eddy simulation is based on Kolmogrov's hypothesis, and done in the inertial range. In inertial range the LES model coefficient is scale-invariant. In many cases, such as computing in the boundary layer, the filter scale is not in the inertial range, and the model coefficient changes drastically with the filter scale, thus the assumption of scale-invariance is not proper. In this paper, we propose a general principle of constraint, and then we deduce two concrete constraints based on the existing spectrum theory and priori data. The constrained dynamic Smogorinsky model can predict energy spectrum well in different range of forced and decayed turbulence. Dynamic mixed models with one of the constraints shows more efficient than some classical models in predicting energy spectrum and SGS dissipation, and also displays a strong correlation with the real stress in different range of the turbulent flows.