Study of internal wave breaking dependence on stratification

TL;DR

This paper investigates how stratification affects internal wave breaking and vortex destruction in fluids, developing a numerical method to analyze the dependence on stratification scale and providing new insights into mixing processes.

Contribution

It introduces a new numerical approach and clarifies the role of stratification scale in vortex destruction and mixing in stratified fluids.

Findings

Vortex destruction increases with stratification scale.

No vortex destruction occurs in constant density fluids.

A mathematical explanation for the stratification dependence is proposed.

Abstract

Mixing effect in a stratified fluid is considered and examined. Euler equations for incompressible fluid stratified by a gravity field are applied to state a mathematical problem and describe the effect. It is found out that a system of Euler equations is not enough for a formulation of correct generalized problem. Some complementary relations are suggested and justified. A numerical method is developed and applied for study of processes of vortex destruction and mixing progress in a stratified fluid. The dependence of vortex destruction on a stratification scale is investigated numerically and it is shown that the effect increases with the stratification scale. It is observed that the effect of vortex destruction is absent when the fluid density is constant. Some simple mathematical explanation of the effect is suggested.