The effect of membraneless initial conditions on the growth of Richtmyer-Meshkov instability
Abstract
The Richtmyer-Meshkov Instability (RMI) is described by the baroclinic generation of vorticity at a density stratified interface when impulsively accelerated. Here, we experimentally investigate the late-time RMI growth of sinuous perturbations of an air/sulfur hexafluoride interface subjected to a Mach 1.2 planar shock wave within the vertical shock tube (VST) facility at Los Alamos National Laboratory. Interface perturbations are established using a novel membraneless technique where cross-flowing Air and SF6 separated by oscillating splitter plate enter the shock tube with an undulating structure. It is found that late-time perturbation growth behavior depends significantly on initial perturbation wavelength and peak-to-valley amplitude as prescribed by the frequency and sweeping angles of the ``oscillating plate''. The results are compared with past nonlinear models for various scaled initial amplitudes (ka0) and used to propose an empirical rational function that captures the asymptotic behavior of perturbation growth for both low and high scaled initial amplitudes.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2019
- Bibcode:
- 2019APS..DFDA33004M