Turbulence in Stratified Fluids

Stratification, the layering of fluid by density, affects turbulence in several ways and on multiple scales. Every fluid element wants to return to the height of neutral buoyancy, but turbulence resists this, producing internal waves, layering, intermittent overturning, and a turbulence structure that looks nothing like the unstratified case. Stratification can feed back on turbulence either positively or negatively, which makes the outcome hard to predict from simple scaling arguments.

We study the mixing of fluids by turbulence in stratified environments, either in isolated regions such as a turbulent patch released into a stably stratified background, or in extended layers. This work was carried out by Dr. Lilly Verso and continues with Marco Boetti.