Anisotropic dynamics and sub-grid energy transfer in wall-turbulence

Abstract

Purpose of the present work is the analysis of the generalized Kolmogorov equation applied to the direct numerical simulation data of a turbulent channel flow. The multi-dimensional description of the anisotropic behavior of turbulent energy production, transport, and dissipation is shown to be relevant for the understanding and modeling of the wall-turbulent physics with special care to the phenomenon of reverse energy flux. These results are proven instrumental also for the correct computation of wall-turbulence when a large eddy simulation approach is considered. The capability of a filtered velocity field to correctly reproduce the wall-turbulent dynamics at different ranges of scales and wall-distances as a function of the filter length will be assessed via filtered direct numerical simulation (DNS) and large eddy simulation data. The possibility of new modeling approaches is also highlighted.