Relationship between coherent Reynolds shear stress and large-scale vortical structures

Abstract

An equation that relates the principal derivative of the Reynolds shear stress and large-scale vorticity fluxes is developed and validated using experimental data in a cylinder near wake. When large-scale vortices prevail, the Reynolds shear stress associated with the coherent motion is a good approximation to the conventional Reynolds shear stress. The latter is essentially determined by the imbalance between the dynamic pressure arising from the streamwise non-homogeneity caused by large-scale vortical structures and the lateral coherent vorticity flux.