Mechanical Engineering ETDs

Publication Date

7-12-2014

Abstract

This thesis presents an experimental study of droplet acceleration in a shock-driven two-phase flow. The study serves to identify the characteristics of the boundary layer growth behind a normal moving shock wave in a shock tunnel. Liquid propylene glycol droplets are pre-mixed with air, and slowly injected into the test section of the shock tunnel. Two test sections are evaluated during the course of this study. Each test section is constructed of square, transparent polycarbonate with internal cross section of 7.62 cm. The first test section contains features on the upper and lower surfaces of the test section, consistent with the holes used for the injection system during earlier Richtmyer-Meshkov Instability studies. The second test section has no surface features interfering with the flow, with smooth interfaces. The quiescent air seeded with propylene glycol droplets (diameter 0.5-3um) is impulsively accelerated with a planar shock wave. A cross-section of the flow is illuminated with multiple pulses from Nd:YAG lasers, producing time-resolved visualizations of the seeded volume. The illuminated images are analyzed to quantify droplet velocity and vorticity from time of shock passage to 400us after shock. Velocity of the shock wave varies between Mach number 1.67 and 2.0. Based on Particle Image Velocimetry interrogation and analysis, a comparison is made between the velocity and vorticity fields in these two test sections.

Keywords

multiphase, shock-driven, boundary layer growth, expansion wave, barrier shock, bleed slot, injection hole, Richtmeyer-Meshkov

Degree Name

Mechanical Engineering

Level of Degree

Masters

Department Name

Mechanical Engineering

First Committee Member (Chair)

Vorobieff, Peter

Second Committee Member

Korotkevich, Alexander

Sponsors

National Nuclear Security Administration

Document Type

Thesis

Language

English

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