MSEE Seminar: Dr. Subith S. Vasu, “Revealing the High-Temperature Destruction of Chemical Weapon Simulants Using Shock Tube and Time-Resolved Laser Diagnostics”

Please contact Veronica Turner for connection information.

Simulants are used in incineration studies, whose chemical structure and combustion rates would be similar to those of chemical warfare (CW) agents. Previous experimental work on these compounds was mainly limited to flow reactors (at temperatures lower than 1000K and at slow heating rates) and flame studies (as dopants), where final product speciation analysis is typically carried out. There are major gaps in our knowledge of the high-temperature decomposition pathways leading to final products and combustion chemistry of CW agents and simulants that are crucial to characterize their burning process, which will help to design better strategies to counter weapons of mass destruction (WMD). Benchmark experiments are needed to validate these estimations, provide insight into high-temperature chemistry, which is not yet accessible by theory, and provide highly accurate values for the most crucial reactions while accommodating the varying fuel structures of both G- and V- agents. Recent experiments utilized a large diameter, high-purity kinetics shock tube facility (which provides very fast heating rates) located at the University of Central Florida (UCF) along with several mid-IR laser absorption spectroscopy techniques for in-situ measurements. Shock tube provides an ideal tool to investigate high-temperature chemical kinetics. Measurements of the concentrations of intermediate species during pyrolysis and oxidation experiments with selected simulants were carried out in the range 800-2200K at several micro-seconds time resolution. Collaborative theoretical calculations of key reaction rates were performed to provide additional insight into the various branching reactions and pathways. Predictive kinetic models for incineration of these compounds were developed based on current experiments and calculations as well as recent work presented in the literature. The current study reveals crucial knowledge related to chemical structural influence on pathways and reactions of simulants. Current research will provide a greater and much-needed fundamental understanding of counter-WMD operations. DOD already uses validated models created from this work in many applied problems and simulations.

Bio: Dr. Subith Vasu (PI) has extensive experience characterizing reacting compounds using laser spectroscopy and shock tube. The PI is a world-leading expert in shock waves, spectroscopy, reacting flows, shock tubes, and species diagnostics. Dr. Vasu is a professor of Mechanical and Aerospace Engineering with a secondary appointment at the College of Optics and Photonics (CREOL). Dr. Vasu’s group (currently 16 Ph.D., 20 undergraduates, and 3 postdocs/research scientists) develops and uses diagnostic sensors for a variety of applications, including energetics, power generation, propulsion, transportation, and explosions. Since his appointment at UCF in 2012 (after his Ph.D. from Stanford University and postdoc training at Sandia Labs), he has authored a plethora of journals (more than 100, including breakthrough publication in the prestigious journal Science and Proceedings of the National Academy of Sciences) and conference articles (more than 200) using laser diagnostics sensors for a variety of problems. An example of high-quality student mentoring is reflected in the fact that more than 85 of these journal publications have been co-authored with his students. He has successfully managed research projects worth more than $15M during his time at UCF.

Dr. Vasu is a recipient of the following prestigious early career awards.: DARPA Director’s Fellowship 2020 (1 out of 13 given in the country); Microsoft Investigator Fellowship (1 out of 15 given in the country); DARPA Young Faculty Award – YFA 2018; Defense Threat Reduction Agency (DTRA) Young Investigator (YIP) 2016; ACS Doctoral New Investigator (YIP equivalent) 2015. Also, he received many highest honors at UCF, including the prestigious “UCF Luminary” and “Reach for the Stars” awards. In 2019, he was selected among 30 participants to represent the U.S. at the prestigious 2019 EU-US Frontiers in Engineering meeting organized by NAE (National Academy of Engineering). Overall, at UCF, the he has an exceptional record in terms of mentoring graduate students and has advised to graduation 15 Ph.D. and 14 M.S. students since 2012, and several of them are employed by DOE/DOD labs and industry. In addition, he has mentored 10 postdocs, 1 Research Associate, and more than 70 undergraduate students.