Page 1 |
Save page Remove page | Previous | 1 of 124 | Next |
|
small (250x250 max)
medium (500x500 max)
large ( > 500x500)
Full Resolution
All (PDF)
|
This page
All
Subset |
DEVELOPMENT OF IMPULSE MEASUREMENT TECHNIQUES
FOR THE INVESTIGATION OF TRANSIENT FORCES DUE
TO LASER-INDUCED ABLATION
by
Brian Charles D’Souza
A Dissertation Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirement for the Degree
DOCTOR OF PHILOSOPHY
(AEROSPACE AND MECHANICAL ENGINEERING)
May 2007
Copyright 2007 Brian Charles D’Souza
Object Description
| Title | Development of impulse measurement techniques for the investigation of transient forces due to laser-induced ablation |
| Author | D'Souza, Brian Charles |
| Author email | bcd@usc.edu |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Aerospace Engineering |
| School | Viterbi School of Engineering |
| Date defended/completed | 2006-03-03 |
| Date submitted | 2007 |
| Restricted until | Unrestricted |
| Date published | 2007-02-27 |
| Advisor (committee member) |
Muntz, E. Phillip Shiflett, Geoffrey Erwin, Daniel |
| Abstract | A torsional impulse balance has been developed as a new diagnostic tool to study fundamental physical processes in micropropulsion systems and laser-surface interactions. With respect to momentum transfer, direct measurements of the transient forces can lead to a better understanding and characterization of the efficiency of the thrust under different configurations. The impulse balance has been designed and tested with a robust calibration system to measure impulsive forces with resolution as low as a few nano-Newton-seconds. A technique has been developed to derive the measured force as a function of time. Time resolved thrust measurements can provide deeper understanding and enhanced characterization of thruster operation for longer duration impulses or multiple pulse applications. In order to directly obtain the specific impulse, modified versions of the impulse balance have been developed to measure impulse and mass loss simultaneously.; Laser propulsion concepts have extensively been discussed since the early 1970s. Ranging from alternative launch solutions to on-orbit maneuvering systems for spacecraft, these concepts have employed an equally diverse range of momentum transfer mechanisms including ablation, shock wave generation, and even photon pressure. Within the scope of laser ablation, a wide variety of physical processes are of interest, which include sputtering, vaporization, and ionization. The conditions for which each physical process might occur and the controlling parameters can be studied by total impulse and time resolved force measurements. For a variety of metal and polymer materials, the impulses due to a range of pulse energies, fluences, pulsewidths, wavelengths, and repetition rates have been investigated. A number of methods for determining the ablated mass have also been examined in order to determine the specific impulse and characterize the materials as possible propellant sources for space propulsion applications. |
| Keyword | impulse measurement; thrust stand; laser ablation; propulsion; ultra-fast laser ablation; laser propulsion |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Type | texts |
| Legacy record ID | usctheses-m260 |
| Rights | D'Souza, Brian Charles |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | http://www.usc.edu/isd/libraries/services/ask_a_librarian/email/ |
| Filename | etd-DSouza-20070227 |
| Archival file | uscthesesreloadpub_Volume29/etd-DSouza-20070227.pdf |
Description
| Title | Page 1 |
| Full text | DEVELOPMENT OF IMPULSE MEASUREMENT TECHNIQUES FOR THE INVESTIGATION OF TRANSIENT FORCES DUE TO LASER-INDUCED ABLATION by Brian Charles D’Souza A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirement for the Degree DOCTOR OF PHILOSOPHY (AEROSPACE AND MECHANICAL ENGINEERING) May 2007 Copyright 2007 Brian Charles D’Souza |
Comments
Post a Comment for Page 1
