Dimensional transition of energy cascades in stably stratified thin fluid layers

TL;DR

This paper investigates how stratification affects energy transfer in thin turbulent fluid layers, revealing a new energy transfer channel and a reduction of inverse cascade in quasi-two-dimensional flows.

Contribution

It demonstrates the impact of stratification on energy cascades in thin layers, highlighting a new transfer channel and changes in cascade behavior.

Findings

Stratification introduces a new energy transfer channel to small scales.

Stratification reduces the inverse energy cascade.

Vortex stretching influences kinetic to potential energy transfer.

Abstract

Numerical simulations of a thin layer of turbulent flow in stably stratified conditions within the Boussinesq approximation have been performed. The statistics of energy transfer among scales have been investigated for different values of control parameters: thickness of the layer and density stratification. It is shown that in a thin layer with a quasi-two-dimensional phenomenology, stratification provides a new channel for the energy transfer towards small scales and reduces the inverse cascade. The role of vortex stretching and enstrophy flux in the transfer of kinetic energy into potential energy at small scales is discussed.