Affiliation
Meeting ID: 714 5365 4820 Passcode: 7yz9s2
Event Type:
MSE Grad Presentation
Date:
Talk Title:
Investigating Shot Parameters Affecting the Dynamic Shock Response of Aluminum Oxide Under Tamped Richtmyer-Meshkov Instability
Location:
​​​​​​​In-person MRDC Room 3515 and via Zoom Video Conferencing
Event Link:
https://us04web.zoom.us/j/71453654820?pwd=XzcOP1GOfWSwfg5KBS1WLj8aCMaNLI.1

Committee Members:

Dr. Naresh Thadhani, MSE (Advisor)

Dr. Min Zhou, MSE

Dr. Anthony Fredenburg, Los Alamos National Lab

 

Investigating Shot Parameters Affecting the Dynamic Shock Response of Aluminum Oxide Under Tamped Richtmyer-Meshkov Instability

Summary: The objective of this research is to provide constitutive models for brittle, granular materials, with new experimental data analyzed to determine the effects of various parameters on the strength response. Dynamic shock compression behavior of aluminum oxide, Al2O3, powder is investigated using a powder-tamped Richtmyer-Meshkov Instability (RMI) experimental design, which probes the interface between a well-understood solid driver, annealed oxygen-free high conductivity copper (OFHC Cu) for this study, and a granular material of interest as the tamper, Al2O3 powder for this study. The RMI phenomenon involves the magnification and growth of an initially perturbed surface under high-pressure conditions produced by shock wave propagation. The material strength response to shock compression is investigated by monitoring the resistance to instability growth through measurements of the final jet length of the driver material into the tamper material.

For the powder-tamped RMI experiments performed in this work, Al2O3 powders with varying tap densities (1.96 g/cc, 2.30 g/cc, and 2.46 g/cc) were used as the tamper material. The overall objective was to determine (a) the effect of the inherent resistance to instability formation and growth affected by varying initial density of the Al2O3 powders, (b) the projectile impact velocity influencing the intensity of shock loading conditions, and (c) kη0, a value representing the relative geometry of the RMI profile as a function of amplitude and wavelength. Measurements of the jet length captured in each of the multiple frames obtained from the various experiments allowed correlation of the effects of projectile velocity, initial density, and kη0 on the final jet length. The data generated in this study is viewed both as a whole dataset and in relevant subsets in order to isolate each primary experimental parameter to avoid confounding contributions to a particular shock response.