Analysis of Kelvin-Helmholtz Instabilities Developing from Oblique Shock Interaction with a Heavy Gas Column

This thesis presents an experimental study of instabilities developing from oblique shock wave interaction with a heavy gas column. For these experiments, the gas column consists of pure sulfur hexafluoride infused with ~11% acetone gas by mass. A misalignment of the pressure and density gradients (from the shock wave) results in three-dimensional vorticity deposition on the gaseous interface. This is the main mechanism responsible for the formation of traditional Richtmyer-Meshkov instabilities (RMI). Other instabilities develop along the interface due to shear between the injected material and the post-shock air (moving at piston velocity behind the column). These instabilities present on the leading (with respect to the shock) and trailing edges of the column. On the leading edge, small perturbations are amplified by shear at the interface. This leads to the development of full billows, or ``cat's eye'' vortices, physically indistinguishable from Kelvin-Helmholtz instabilities (KHI). Certain characteristics of the KHI, such as initial instability growth rate and wavelength (lambda), depend on several factors including the Mach number of the shock wave, the shock tube angle of inclination (theta), and the post-shock compressed size of the column.

Name thesis:degree_name

Mechanical Engineering

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Mechanical Engineering

Year

2016

Author dc:creator

• Wayne, Patrick

Contributors dc:contributor

• Vorobieff, Peter
• Truman, C. Randall

• shock
• wave
• Kelvin-Helmholtz
• instability
• Planar Laser Induced Fluorescence
• oblique

Language dc:language

English

Identifier

https://digitalrepository.unm.edu/me_etds/41

OAI identifier oai:identifier

oai:digitalrepository.unm.edu:me_etds-1040