Effect of magnetic field on temporal development of Rayleigh-Taylor instability induced interfacial nonlinear structure

TL;DR

This paper investigates how magnetic fields influence the nonlinear growth of Rayleigh-Taylor instability at fluid interfaces, revealing conditions under which magnetic pressure can suppress or enhance instability growth.

Contribution

It provides new insights into the nonlinear effects of magnetic fields on Rayleigh-Taylor instability, especially when magnetic fields are present on both sides of the interface.

Findings

Magnetic fields can suppress or enhance instability depending on their orientation and location.

Magnetic pressure can cause periodic undulations of the interface surface.

Results differ from classical linear theory predictions.

Abstract

The effect of magnetic field on the nonlinear growth rate of Rayleigh-Taylor instability induced two fluid interfacial structures has been investigated. The magnetic field is assumed to be parallel to the plane of the two fluid interface and acts in a direction perpendicular to the wave vector. If magnetic field is restricted only to either side of the interface the growth rate may be depressed (may almost disappear) or be enhanced depending on whether the magnetic pressure on the interface opposes the instability driving pressure difference g({\rho}h - {\rho}l)y or acts in the same direction. If magnetic field is present on both sides of the two fluid interface, stabilization may also take place in the sense that the surface of separation undulates periodically when the force due to magnetic pressure on two sides are such as to act in opposite direction. This result differs from the classical linear theory result which predicts that the magnetic field parallel to the surface has no influence on the growth rate when the wave vector is perpendicular to its direction.