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

Brunkow, Samuel Neal

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

Description

Title

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

Author(s)

Brunkow, Samuel Neal

Issue Date

2024-05-01

Director of Research (if dissertation) or Advisor (if thesis)

Glumac, Nick G

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• fireball
• pyrometry
• spectroscopy
• imaging
• high explosive
• secondary explosive
• structure

Abstract

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.

Graduation Semester

2024-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2024 Samuel Brunkow

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