Application of Turbulence Model to Stratified Shear Flow

Buoyancy generated turbulence in stably stratified flow with shear

The energy evolution in buoyancy-generated turbulence subjected to shear depends on the gradient Richardson number Ri and the stratification number St, which is a ratio of the time scale of the initial buoyancy fluctuations to the time scale of the mean stratification. During an initial period, the flow state evolves as in the unsheared case. After this period, shear generates fluctuating veloc...

Numerical experiments on strongly stratified homogeneous shear turbulence

Turbulence in strongly stable density stratification is a common phenomenon in atmosphere and in oceans and other large water bodies. Stably and strongly stratified turbulence have been studied in many experimental and numerical studies. A characteristic feature of strongly stratified turbulence observed in several studies is the formation of quasi-horizontal layers. During the last decade, the...

Radiation Instability in a Stratified Shear Flow

The paper deals with a new mechanism of instability in stratified fluid caused by internal wave radiation from a shear layer. This radiation instability may be explained in terms of the negativeenergy wave concept. These waves are able to grow due to radiation losses. The dispersion relation and non-linear stage of the process are analyzed through a model with tangential velocity discontinuity....

A Buoyancy–Vorticity Wave Interaction Approach to Stratified Shear Flow

Motivated by the success of potential vorticity (PV) thinking for Rossby waves and related shear flow phenomena, this work develops a buoyancy–vorticity formulation of gravity waves in stratified shear flow, for which the nonlocality enters in the same way as it does for barotropic/baroclinic shear flows. This formulation provides a time integration scheme that is analogous to the time integrat...

A Computational Study of Transition to Turbulence in Shear Flow