Direct numerical simulation of stationary homogeneous stratified sheared turbulence

Using direct numerical simulation (DNS), we investigate stationary and homogeneous driven turbulence in various stratifications, ranging from neutral to very stable. The Taylor Reynolds number is about 400, allowing an adequate separation of scales for the study of stratified turbulence dynamics. Analysis of the simulations is used to elucidate several aspects of stratified turbulence, including flux--gradient relations, length scales, spectra, the formation of layer, and criteria of turbulence collapse.