Multiple time-scale turbulence model for wall and homogeneous shear flows based on direct numerical simulations

Abstract

The k-ϵ model is widely used and has proved effective in predicting wall shear layer turbulence. These models, however, perform poorly in prediction of homogeneous shear flows. Such inconsistency is not caused by crudeness of the eddy-viscosity approximation, but by inappropriate estimation of the relevant time-scale of turbulence. Thus, to settle this problem, we propose a low-Reynolds number-type “multiple time-scale” turbulence model on the basis of recent direct numerical simulations (DNS) of turbulence. Making a proposed model that is applicable to prediction of near-wall turbulent flows without the controversial wall functions and on reproducing the wall-limiting behavior of turbulence quantities is the emphasis. The proposed model has been tested in wall shear flows with and without a pressure gradient. We also tested the present model in homogeneous flows with and without mean strain. Assessments based on the latest DNS data and measurements indicate that the present model works well, regardless of the flow regimes.