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Title: Effect of initial perturbation amplitude on Richtmyer-Meshkov flows induced by strong shocks

We systematically study the effect of the initial perturbation on Richtmyer-Meshkov (RM) flows induced by strong shocks in fluids with contrasting densities. Smooth Particle Hydrodynamics simulations are employed. A broad range of shock strengths and density ratios is considered. The amplitude of the initial single mode sinusoidal perturbation of the interface varies from 0% to 100% of its wavelength. The simulations results are compared, wherever possible, with four rigorous theories, and with other experiments and simulations, achieving good quantitative and qualitative agreement. Our study is focused on early time dynamics of the Richtmyer-Meshkov instability (RMI). We analyze the initial growth-rate of RMI immediately after the shock passage, when the perturbation amplitude increases linearly with time. For the first time, to the authors' knowledge, we find that the initial growth-rate of RMI is a non-monotone function of the initial perturbation amplitude, thus restraining the amount of energy that can be deposited by the shock at the interface. The maximum value of the initial growth-rate depends on the shock strength and the density ratio, whereas the corresponding value of the initial perturbation amplitude depends only slightly on the shock strength and density ratio.
Authors:
;  [1] ;  [2]
  1. Mellon College of Science and Carnegie Mellon University – Qatar, Carnegie Mellon University, Pittsburgh, Pennsylvania 15231 (United States)
  2. Stellingwerf Consulting, Huntsville, Alabama 35803 (United States)
Publication Date:
OSTI Identifier:
22493748
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 9; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 42 ENGINEERING; AMPLITUDES; COMPUTERIZED SIMULATION; DENSITY; DISTURBANCES; ENERGY ABSORPTION; FLOW MODELS; FLUIDS; HYDRODYNAMICS; INSTABILITY; SHOCK WAVES