Experimental Characterization of Turbulence Produced in a Shock Tube: A Preliminary Work for the Study of the Turbulent Gaseous Mixing Induced by the Richtmyer-Meshkov Instability

Abstract

The Richtmyer-Meshkov Instability (RMI) occurs in several physical and technological processes such as supernova explosion, supersonic combustion, detonics or inertial confinement fusion. This instability develops when interfacial perturbations, between two fluids of different densities, grow because of a shock wave induced impulsive acceleration. The basic mechanism for the initial growth of perturbations on the interface is the baroclinic generation of vorticity which results from the misalignment of the pressure and density gradientswhen the shock crosses the interface. Early time linear and following nonlinear growth of the RMI have been, and are still widely investigated, either theoretically, numerically and experimentally [1]. Nevertheless, experimental investigation of the Turbulent Mixing Zone (TMZ) induced by a rapidly growing RMI is still nowadays poorly documented, even if we can mention for instance the work of Leinov et al. [2] who characterized the growth of the MZ with time following the passage of the re-shock (with an emphasis on the influence of the initial amplitude of the MZ and the reshock strength), and the study of Poggi et al. [3] in which the production of turbulence by the TMZ has been investigated in a vertical shock tube using two-components Laser Doppler Velocimetry (LDV).