Mechanical Engineering ETDs

Author

Ross White

Publication Date

8-27-2012

Abstract

This thesis presents an experimental study of fluid instabilities formed due to an oblique interatction of a shock wave with a cylindrical gas column seeded with glycol droplets. Two gases are injected into quiescent air to form the column. The first is sulfur hexafluoride (SF6) which generates the well-known Richtmyer-Meshkov Instability (RMI) when impulsively accelerated by a shock wave. This instability is formed due to the misalignment of the pressure and density gradients during the acceleration phase. The second is air. In this case, there is no macroscopic density gradient between the gas column and the surrounding air. Nonetheless, an instability similar to RMI develops due to the presence of the glycol droplets. Experimental studies are performed at an oblique angle of 15 degrees and a Mach number of 1.67. Experiments of this nature typically make an assumption that the cylindrical gas column is nominally two-dimensional to simplify the problem. The validity of this assumption is explored by investigating the morphology of the instabilities in multiple horizontal planes and a vertical plane. Major variations of the morphology only occur near the bounding walls, with less variation far from these walls. An investigation of the rotation of the gas column is also presented.

Keywords

Unsteady flow (Fluid dynamics), Shock (Mechanics), Gas tubes.

Degree Name

Mechanical Engineering

Level of Degree

Masters

Department Name

Mechanical Engineering

First Advisor

Vorobieff, Peter

First Committee Member (Chair)

Kumar, Sanjay

Second Committee Member

Poroseva, Svetlana

Third Committee Member

Truman, C. Randall

Sponsors

This work was funded by US National Nuclear Security Agency (NNSA) under the Stewardship Science Academic Alliances program through DOE Grant DE-PS52-08NA28920 and by the US Defense Threat Reduction Agency (DTRA) under awards HDTRA1-07-1-0036 and HDTRA1-08-1-0053. Without this funding, none of this work could have been performed.

Document Type

Thesis

Language

English

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