Mesoscaling of Reynolds Shear Stress in Turbulent Channel and Pipe Flows

摘要

Experimental and numerical data of the Reynolds shear stress in turbulent channel and pipe flows under a mesonormalization are presented. The mesolength scale associated with this normalization is intermediate to the traditional inner and outer lengths. Justification for the mesoscales is provided by a direct analysis of the mean momentum equation. Specifically, the mesonormalization is revealed through a rescaling that appropriately reflects the physics of an internal mesolayer within which a balance breaking, and subsequent balance exchange of terms in the mean momentum equation takes place. Direct numerical simulation and experimental data are examined and shown to be in good agreement with the new scaling, supporting the new theory.