Richtmyer–Meshkov instability on a low Atwood number interface after reshock

Abstract

The Richtmyer-Meshkov instability after reshock is investigated in shock tube experiments at the Wisconsin Shock Tube Laboratory using planar laser imaging and a new high speed interface tracking technique. The interface is a 50-50% volume fraction mixture of helium and argon stratified over pure argon. This interface has an Atwood number of 0.29 and near single mode, two-dimensional, standing wave perturbation with an average amplitude of 0.35 cm and a wavelength of 19.4 cm. The incident shock wave of Mach number 1.92 accelerates the interface before it is reshocked by a reflected Mach 1.70 shock wave. The amplitude growth after reshock is reported for variations in this initial amplitude, and several amplitude growth rate models are compared to the experimental growth rate after reshock. A new growth model is introduced, based on a model of circulation deposition calculated from one-dimensional gas dynamics parameters. This model is shown to compare well with the amplitude growth rate after reshock and the circulation over a half-wavelength of the interface after the first shock wave and after reshock.4 5

Freeze-out of perturbation growth of single-mode helium–air interface through reflected shock in Richtmyer–Meshkov flows

“…A reflected shock has generally been produced through an incident shock reflecting from a rigid wall (Weber et al. 2012; Jacobs et al. 2013; Mohaghar et al.…”

“…In experiments, two successive shock waves are difficult to generate in an ordinary shock tube and, therefore, experimental studies on freeze-out of a heavy-light interface perturbation are rare. A reflected shock has generally been produced through an incident shock reflecting from a rigid wall (Weber et al 2012;Jacobs et al 2013;Mohaghar et al 2019;Guo et al 2022). Such a reflected shock, however, is often too strong to realize freeze-out of a light-heavy perturbation.…”

Shock-tube studies of single- and quasi-single-mode perturbation growth in Richtmyer–Meshkov flows with reshock

“…In reshock experiments with initial single-mode (Collins & Jacobs 2002; Weber et al. 2012) or quasi-single-mode (Hahn et al. 2011; Mohaghar et al.…”

“…In these singly shocked experiments, the fundamental mode of quasi-single-mode interfaces was found to dominate the perturbation growth with similar evolutions of the single-mode interface. In reshock experiments with initial single-mode (Collins & Jacobs 2002;Weber et al 2012) or quasi-single-mode (Hahn et al 2011;Mohaghar et al 2017Mohaghar et al , 2019 interfaces, light/heavy configurations (the incident shock propagates from the light fluid to the heavy fluid) are often considered, while studies with heavy/light configurations (the incident shock propagates from the heavy fluid to the light fluid) seem to be rare (Hahn et al 2011). More importantly, most classical theories proposed for singly shocked cases (Richtmyer 1960;Sadot et al 1998;Dimonte & Ramaprabhu 2010;Zhang & Guo 2016) or reshock cases (Mikaelian 1989(Mikaelian , 2011(Mikaelian , 2015Charakhch'yan 2000) have been frequently tested in the experiments with an initial light/heavy interface (Vetter & Sturtevant 1995;Leinov et al 2009;Morgan et al 2012;Weber et al 2014;Mansoor et al 2020).…”