Modal model for the nonlinear multimode Rayleigh{endash}Taylor instability

Journal Article · Thu Aug 01 04:00:00 EDT 1996 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871655· OSTI ID:286358

Ofer, D ^[1]; Alon, U ^[2]; Shvarts, D ^[1]; McCrory, R L; Verdon, C P ^[3]

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1. Nuclear Research Center Negev, P.O. Box 9001, Beer-Sheva 84190 (Israel)
2. Physics of Complex Systems, Weizmann Institute of Science, Rehovot (Israel)
3. Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299 (United States)

A modal model for the Rayleigh{endash}Taylor (RT) instability, applicable at all stages of the flow, is introduced. The model includes a description of nonlinear low-order mode coupling, mode growth saturation, and post-saturation mode coupling. It is shown to significantly extend the range of applicability of a previous model proposed by Haan, to cases where nonlinear mode generation is important. Using the new modal model, we study the relative importance of mode coupling at late nonlinear stages and resolve the difference between cases in which mode generation assumes a dominant role, leading to the late time inverse cascade of modes and loss of memory of initial conditions, and cases where mode generation is not important and memory of initial conditions is retained. Effects of finite density ratios (Atwood number {ital A}{lt}1) are also included in the model and the difference between various measures of the mixing zone penetration depth for {ital A}{lt}1 is discussed. {copyright} {ital 1996 American Institute of Physics.}

• OSTI ID: 286358
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 8 Vol. 3; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CONVECTIVE INSTABILITIES
ICF DEVICES
LASER-PRODUCED PLASMA
PLASMA INSTABILITY
PLASMA SIMULATION
RAYLEIGH-TAYLOR INSTABILITY