Experimental Study of the Richtmyer-Meshkov Instability on Inclined Interface

摘要

The RichtmyerMeshkov instability (RMI) is a hydrodynamic instability resulting from animpulsive acceleration of a density gradient. This instability was first described in thetheoretical work of Richtmyer [2], and later in the experimental work of Meshkov [3]. Thetwo primary ingredients for the RMI are an impulsive acceleration which takes the form ofan instantaneous pressure gradient, and a fluid interface which generates a density gradientthat is misaligned with the pressure gradient. To further our investigation of the RMI aninitial condition experiment needed to be conducted. At the Texas A&M Shock Tube andAdvanced Mixing Lab (STAML) there is a Mach 3 capable shock tube, used to study theRMI. It was necessary to study the initial conditions of the interface to understand its effectson the development of the RMI at post-shocked times. From this we were able to determinecharacteristic flow qualities present on the interface prior to the shock. Within the initialconditions investigation was a qualitative study conducted to determine the vorticity of theinterface. The vorticity study was to show how much energy the shock wave deposits, and aidin development of a controlled perturbation of the interface. In the case of the qualitativevorticity study, little was learned due to problems encountered involving Particle ImageVelocimetry (PIV) imaging. However, a method for controlled perturbation techniques wasdiscovered involving the flow characteristics at the interface.