EFFECTS OF SHEAR AND ROTATION ON TURBULENT FLOW IN A STRATIFIED FLUID

The effect of rotation on the evolution of turbulence in a stably stratified shear flow is studied using direct numerical simulations. The prototypical example of this flow is considered here with uniform vertical shear, constant system rotation about the vertical axis, and uniform vertical stable density stratification. In the absence of rotation, growth of the turbulent kinetic energy is observed for weakly stratified flows. As the stratification is increased, the growth of the turbulent kinetic energy weakens and decay is observed for strongly stratified flows. Counter-gradient fluxes are observed in the strongly stratified cases. For moderate stratification, rotation leads to a stronger growth of the turbulent kinetic energy. For strong stratification, however, virtually no effect of rotation on the evolution of the turbulent kinetic energy was observed for the range of parameters studied here. The tendency for counter-gradient fluxes was observed to decrease with increasing rotation for strongly stratified flow.