Dissipation scaling in constant-pressure turbulent boundary layers

Abstract

Using results from previous direct numerical simulations and experiments in the outer region of spatially evolving turbulent boundary layers, we compute the streamwise evolution and the wall-normal variation of the dissipation parameter CE, namely, the turbulent kinetic energy dissipation rate, normalized by appropriate powers of the local turbulent kinetic energy and integral length scale. For Reθ3 10000 (Reθ is a Reynolds number on the freestream velocity and the local momentum thickness), CE is essentially constant in the streamwise direction, but varies by up to 50% in the wall-normal direction. For Reθ<10000, CE is additionally found to vary in the streamwise direction and is inversely proportional to the local turbulence Reynolds number Reλ.