Rayleigh--Taylor eigenmodes of a thin layer in the nonlinear regime

Journal Article · Sun May 01 00:00:00 EDT 1994 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.870725· OSTI ID:6930167

Basko, M M ^[1]

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1. Joint Institute for Laboratory Astrophysics, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440 (United States)

In the long-wavelength limit, many aspects of the Rayleigh--Taylor (RT) instability of accelerated fluid shells can be explored by using the thin sheet approximation. For two-dimensional (2-D) planar eigenmodes, analytic nonlinear solutions [E. Ott, Phys. Rev. Lett. [bold 29], 1429 (1972)] are available. Comparing the simplest of them for the nonconstant acceleration, [ital g][proportional to][ital t][sup [minus]2], with Ott's solution for constant [ital g], the applicability of nonlinear results obtained for constant [ital g] to situations with variable acceleration is analyzed. Nonlinear three-dimensional (3-D) effects are investigated by comparing the numerical solutions for axisymmetric Bessel eigenmodes with Ott's solution for 2-D modes. It is shown that there is a qualitative difference between 2-D and 3-D bubbles in the way they rupture a RT unstable fluid shell: In contrast to the exponential thinning of 2-D bubbles, mass is fully eroded from the top of an axisymmetric 3-D bubble within a finite time of (1.1--1.2)[gamma][sup [minus]1] after the onset of the free-fall stage; [gamma] is the RT growth rate.

• OSTI ID: 6930167
• Journal Information: Physics of Plasmas; (United States), Vol. 1:5; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
RAYLEIGH-TAYLOR INSTABILITY
EIGENFUNCTIONS
ABLATION
ANALYTICAL SOLUTION
BESSEL FUNCTIONS
BUBBLES
INERTIAL CONFINEMENT
INSTABILITY GROWTH RATES
CONFINEMENT
FUNCTIONS
INSTABILITY
PLASMA CONFINEMENT
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