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

A statistical characterization of a vertical shock tube is carried out using Laser Doppler Velocimetry (LDV) and time-resolved Schlieren visualizations. The behaviour of the mean velocity field as well as the turbulence levels produced behind the shock wave are investigated for different homogeneous medium (pure air) configurations. This allows to determine the background turbulence level of the shock-tube itself. In future work, the turbulent mixing zone induced by a rapidly growing Richtmyer-Meshkov Instability will be studied in the same experimental apparatus. It will then be possible to extract the specific baroclinic turbulence production due to the mixing itself from the background turbulent "noise" of the shock-tube. An attempt is moreover made in this work to clarify the influence of the presence of the fragments of a nitrocellulose membrane in the test section on the statistical convergence of the turbulent data