Keywords and Phrases
"When tests using pressure to characterize the performance or effects of an explosive are conducted in laboratory or other small scale, highly controlled settings, it is expected that any gages will be ideally mounted and there will not be any surface imperfections or roughness near the gage location. However, when explosive tests are scaled up, the test beds typically do not have perfect surfaces. Instead there may be rough surfaces with various types of geometry or situations where it is extremely difficult to get the gage flush mounted with a flat surface. In a time where tests with multiple replications are increasingly limited, it is critical to understand the experimental error present in a test.
This document discusses pressure and optical data gathered from shock tube tests for flat and rough surfaces spanning two geometries and three amplitudes as well as three different imperfect mounting configurations.
For each test, pressure data was recorded from gages mounted in the roughness plates and on a wing mount to provide information on how the measured pressure varied due to the location of the gage. In addition to the pressure data, Schlieren video was recorded for each shot on the same timebase as the pressure gages. Both geometry and amplitude of the roughness affected the shock structure and corresponding pressure waveform. The combination of pressure data and Schlieren video allowed particular waveform characteristics to be attributed to specific shock structures.
With the roughness plates in place, the measured pressure varied from 12 to 85% higher than the baseline, while the impulse varied from 6% lower to 49% higher. The gage mounted on the wing at 7-inches above the floor of the shock tube remained unaffected during the test series, with only a 4% variance in peak pressures and impulses"--Abstract, page iii.
Baird, Jason, 1955-
Worsey, Paul Nicholas
Isaac, Kakkattukuzhy M.
Maerz, Norbert H.
Ph. D. in Explosives Engineering
Missouri University of Science and Technology
xii, 190 pages
© 2015 Laurin Ashley Bookout, All rights reserved.
Dissertation - Open Access
Explosives -- Testing
Pressure -- Measurement
Schlieren methods (Optics)
Electronic OCLC #
Bookout, Laurin Ashley, "Analysis of effects of surface roughness and local surface imperfections on measured pressure" (2015). Doctoral Dissertations. 2438.