Analytical modeling of magnetic Rayleigh-Taylor instabilities in compressible fluids

Journal Article · Sat Nov 15 04:00:00 EST 2008 · Physics of Fluids (1994)

DOI:https://doi.org/10.1063/1.3025832· OSTI ID:21175782

Liberatore, Stephane; Bouquet, Serge ^[1]

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1. CEA, DAM, DIF, F-91297 Arpajon (France)

The magnetic Rayleigh-Taylor instability (MRTI) is investigated in the case of compressible plasmas. The goal of this work is highlighting the influence of both the magnetic field and the compressibility of the material on the growth rate of the Rayleigh-Taylor instability, compared to the classical growth rate derived for incompressible fluids. Our analytical linear models are derived in the framework of the ideal magnetohydrodynamics theory. Three general dispersion relations are obtained: (1) Two for stratified fluids, including compressible (denoted CS{sub parallel} when the wave vector k is parallel to the equilibrium magnetic field B{sub 0} and CS{sub perpendicular} when k perpendicular B{sub 0}) and incompressible (denoted IS{sub parallel}) and IS{sub perpendicular} and (2) one for incompressible uniform density fluids, including finite mass (denoted Ifm) and infinite (denoted IU). For k perpendicular B{sub 0}, Ifm, IU, and IS{sub perpendicular} are unmagnetized cases. Comparisons of those various configurations are performed and several differences are pointed out. The main results are as follows: Stratification weakens the MRTI while compressibility has a destabilizing effect. The magnetic field enhances these phenomena. The CS{sub parallel} and IU configurations have an identical cutoff wave number. The upper fluid (also called heavy fluid) is more sensitive to compressibility than the light one when k parallel B{sub 0}. Finally, the CS{sub parallel} case is more sensitive than the CS{sub perpendicular} one to physical variations.

• OSTI ID: 21175782
• Journal Information: Physics of Fluids (1994), Journal Name: Physics of Fluids (1994) Journal Issue: 11 Vol. 20; ISSN 1070-6631; ISSN PHFLE6
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMPRESSIBILITY
DISPERSION RELATIONS
FLUIDS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
PLASMA
RAYLEIGH-TAYLOR INSTABILITY
SIMULATION
STRATIFICATION