SUBJECT: Ph.D. Dissertation Defense
BY: John Carter
TIME: Wednesday, July 15, 2020, 1:30 p.m.
TITLE: Statistical and Temporal Analysis of Shock-Driven Instability Through Simultaneous Density and Velocity Measurements
COMMITTEE: Dr. Devesh Ranjan, Chair (ME)
Dr. Peter Loutzenhiser (ME)
Dr. Wenting Sun (AE ME)
Dr. Robert Gore (LANL)
Dr. Joseph Oefelein (AE)
Dr. Ellen Yi Chen Mazumdar (ME)


The effects of initial conditions (single- and multi-mode) and nondimensional density ratio (Atwood number, A) on dynamics of mixing in Richtmyer--Meshkov Instability evolution are studied using high resolution results from ensembles of experiments as well as temporally resolved measurements, all utilizing simultaneous PLIF and PIV. Campaigns were undertaken at an incident shock Mach number of 1.55 on both single and multi-mode perturbed interfaces between two gas pairs before and after reshock. This was done to hold constant as many parameters as possible between the cases. The gas pairs used were Nitrogen/Carbon Dioxide and Nitrogen/Sulfur Hexafluoride, where the incident shock travels from light (Nitrogen) to heavy gas. These gas pairs yield Atwood numbers of 0.22 and 0.67, respectively. This constitutes the first work where turbulence statistics resulting from ensemble averaging are collected on both of these Atwood numbers, and also the first comparison of Atwood numbers with otherwise parametric consistency where turbulence statistics from ensemble averaging can be compared. Furthermore, the high speed measurements in this flow are the first temporally resolved simultaneous PLIF and PIV measurements collected for RMI flows. This allows calculation of time-resolved quantities and time-correlated analysis of features from robust measurements. The defense will be presented via BlueJeans: Meeting ID: 493730453 or Dial: 1.408.419.1715 and enter the Meeting ID followed by #