dc.description.abstract | An experimental study of the Richtmyer-Meshkov instability (RMI) is presented
here for the twice-shocked, or reshocked, inclined interface perturbation. Experiment
work was conducted in the shock tube facility in the Advanced Fluid Mixing Lab at
Texas A&M University. Experimental cases were performed at a single Atwood number
(0.23), Mach number (1.55) and inclination angle (60°) with a perturbation amplitude-to-wavelength
ratio of 0.29. Mie scattering and particle image velocimetry (PIV) data was
collected using a planar laser system and was used to compute mixing width, vorticity
and circulation.
Experimental cases were defined by the time which the interface was allowed to
develop before reshock interaction. Cases 1, 2 and 3 were defined for development
times of 1.635 ms, 3.5 ms and 5.105 ms respectively. Developmental time series were
created using Mie scattering images from multiple experimental runs for each case and
mixing width data was derived from the time series images. Interface growth rates post-reshock
are computed using mixing width and interface length measurements. PIV data
for pre- and post-reshock times were used to create vorticity plots for a qualitative
discussion of the effect of reshock on the interface and estimate the circulation deposited
on the flow field by reshock. Results indicate that the longer the initial interface is
allowed to develop prior to reshock interaction, the greater the circulation post-reshock
and change in circulation across the reshock interaction. Turbulent kinetic energy
spectra for all cases are computed as well as the turbulent length scales of the flow based on mixing width, circulation and interface length. | en |