On diffusion of turbulent energy in plane Couette flow

This study addresses the possible existence of significant counter-gradient diffusion of turbulent energy from the centre towards the walls in plane Couette flow. Data from a direct numerical simulation disprove the counter-gradient diffusion hypothesis and reveal that the turbulent energy production is nearly balanced by the energy dissipation throughout the core region. The results of the simulation are more plausible than the most comprehensive set of measurements available today.