Near-wall second moment closure based on DNS analysis of pressure correlations

Abstract

The purpose of the present paper is to use recent DNS results for the quadruple decomposition of pressure fluctuations in wall turbulence (rapid/slow and volume/wall terms) in the development of a new near-wall wall-normal free second-moment closure for wall-bounded flows. Based on the comparison of existing models with DNS results we propose the addition of new inhomogeneous terms in the tensorial representations for pressure diffusion and for pressure-strain redistribution, and calibrate the proposed representations both a priori and a posteriori. The resulting model is then assessed by comparison with experimental data for flat-plate boundarylayer, separating diffuser and shock-wave/boundary-layer interaction flows. The overall behavior of the model is quite satisfactory and we analyze in detail the particular points which can be improved. These drawbacks, mainly related with the wall-layer asymptotic behavior of the Reynolds-stresses, are common to many existing closures, and it is suggested that to improve this behavior a model including transport equations for the components of the dissipation tensor should be developed. * Institut d'Alembert, case 161, 4 place Jussieu,