SUMMARY

The fluid mixing caused by variable-density instabilities is important in a wide variety of scenarios from ocean mixing and astrophysical phenomena to nuclear fusion techniques and atomic weapons. This thesis explores the mixing resulting from a specific instability known as the Blast-Driven Instability (BDI). Using high speed experimental techniques, the first fully time-resolved observations of the BDI are made. These observations are then used to test two common mixing models (RANS and LES) in a digital-twin simulation designed to precisely match the novel facility used in the high-speed experiments. Simulation results are analyzed against the data and reasons for their agreement, or lack thereof, are explored in detail. The experimental data is used in conjunction with the simulation results to explore the BDI's sensitivity to two key governing parameters. How changes in the governing parameters create qualitative and quantitative changes in the BDI's behavior is explored extensively. Finally, various scaling attempts are investigated in an attempt to decipher how the mixing induced by the BDI can be explicitly linked to the parameters. The virtual component of the defense will be held through Teams. The link is here: https://teams.microsoft.com/l/meetup-join/19%3ameeting_MzNlNWZjZWQtZjE0Mi00MjYzLTgyMmQtNDY5M2QyMmZjOTBi%40thread.v2/0?context=%7b%22Tid%22%3a%22482198bb-ae7b-4b25-8b7a-6d7f32faa083%22%2c%22Oid%22%3a%22460f22cd-4008-4ec7-9e51-87e47c46acb2%22%7d