Optical Physics of Explosive Fireballs
Shao Lee Soo Professor of Mechanical Science & Engineering
University of Illinois, Urbana-Champaign
Fireballs generated by high explosives represent a class of complex thermochemical environments that, despite their utility in engineering and military applications, remain challenging to simulate accurately. Flows are transient and three-dimensional. They involve non-equilibrium effects requiring explicit chemical modeling, and they often consist of multiple phases. Optically, the light emissions from fireballs are similarly complex, temporally and spatially. Early time signatures show extreme, plasma-like conditions, and later-time optical signatures are complicated by spatial property variations, optical depth issues, and limited information on emissivities of explosively generated particulates. This talk discusses the optics of fireballs, covering the evolution of emitted light from an explosive event, with an emphasis on spectroscopic emission measurements. Insight gained in these measurements has led to optical measurements within the fireball itself, primarily in absorption. These measurements are reviewed, and the current state of the art of in-fireball spectroscopy is discussed, with emphasis on the next generation of measurement technologies.
Nick Glumac is the Shao Lee Soo Professor of Mechanical Science & Engineering at the University of Illinois, Urbana-Champaign. He received his Ph.D. from Caltech in 1994. His research focusses on spectroscopy of reacting flows with emphasis on flows involving energetic materials, especially explosives. He is the recipient of a handful of minor awards, most of which were obtained by dubious means. His greatest accomplishments include assisting in research work performed by legendary scientists Tim Weihs, Mike Zachariah, and Ed Dreizin.