Don’t Blink! Seeing and defining high-temperature chemistry on the microsecond scale

Abstract:
Launching the next generation of satellites, producing high-fidelity nano-materials, and
preventing fire spread all rely on complex phase change and rapid chemical reactions. However,
the coupling of these processes as well as the fundamental reaction kinetics is poorly understood
owing in large part to the difficulty in observing the highly reactive phenomena on relevant time
and length scales. In this talk, I outline a multi-method approach for applying optical diagnostics
and novel modelling techniques in complex operating environments to identify key drivers of
reactivity, including multi-phase interactions and key gas-phase reaction mechanisms with a
focus on the novel analytical methodologies developed. Key to many of these processes is the
high-temperature gas-phase reactivity of base fuels or stable intermediates, with the potential for
reaction mechanisms defining millisecond scale phenomena to encompass hundreds of possible
reactions. I will highlight the role of highly repeatable shock tube experiments with high-fidelity
diagnostics in unlocking the fast kinetics (<10 µs) behind these complex processes as well as
how we utilize the laser induced shocking of solid materials to understand their thermal
decomposition in extreme environments. In addition to highlighting the role of temperature on
the gas-phase chemistry, I will also focus on the role of pressure in driving the multi-phase
reactivity and phase change in propellant and energetic material applications.

Biography:
Dr. Rachel Schwind is a Lecturer in Experimental Thermofluids at the University of
Edinburgh. Her expertise is in reaction kinetics and complex phase change with a focus on novel
reactive materials and high-pressure heterogeneous chemistry with applications inculding green
propulsion, materials synthesis, and energetic materials. Dr. Schwind’s research focuses on
merging fundamental chemical kinetics studies with complex application environments,
including the development of novel analytical techniques and experimental design to provide
improved understanding of key reactive drivers and kinetic pathways. Prior to joining the
University of Edinburgh, Dr. Schwind was at Brown University, first as a postdoc and then as a
Senior Research Associate overseeing the experimental activity in the Goldsmith Lab for
Chemical Kinetics. She recieved her Masters and PhD in Mechanical Engineering from the
University of Michigan, during which time she served as a visiting researcher at Argonne
National Laboratory, first through a US Department of Energy SCGSR Fellowship and then as
an NSF Intern. Her expertise in fast reaction kinetics of novel systems has been recognized with
multiple invited seminars and panels, including selection for the Future of Combustion Research
specialist panel by the Combustion Institute and a 40 under 40 e-Lecture on Combustion.