Thermal and physical structures of high explosive fireballs through optical thermometry and high-speed imaging

Secondary high explosives including Composition A-5, PBXN-5, TNT, Composition B, PETN, and one metalized explosive, RDX-AL, were tested to characterize detonation fireball physical and thermal structures. Hemispherical 25-gram charges were detonated on a transparent PMMA sheet enabling optical measurements with a basal view of the fireball’s internal structure. Temperature profiles were determined through pyrometry and blackbody fitting of binned imaging spectra. The 3-color pyrometry was employed at three radial distances from the detonation center with sub microsecond temporal resolution utilizing optical fiber installed flush with the transparent sheet for light capture at 700, 900, and 1300 nm. Imaging spectra, captured at a flame front radius of approximately 3 to 4.5 inches, facilitated measurement of the thermal distribution across the flame front. Additionally, an HFSC Pro framing camera was utilized to capture the fireball directly on and as viewed from underneath. The high-speed imaging facilitated spatial characterization of the internal fireball structure at 4 diameters and qualitative assessments of hydrodynamic instabilities and relative turbulent mixing. Measurements and observations are compared with current literature and state-of-the-art theoretical models.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Brunkow, Samuel Neal

Contributors dc:contributor

• Glumac, Nick G

• Fireball
• Pyrometry
• Spectroscopy
• Imaging
• High Explosive
• Secondary Explosive
• Structure

Statement dc:rights

• Copyright 2024 Samuel Brunkow

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/124425

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F124425