When flow physics obscures chemistry: Non-ideal boundary layer growth in shock tube kinetics studies
Princeton University
Abstract
Pressure-driven shock tube facilities are widely used to study high-temperature, gas-phase reaction kinetics. In reflected-shock experiments, non-ideal facility effects such as incident shock wave attenuation and boundary layer growth can lead to changing thermodynamic conditions in the facility test section. In turn, these transient conditions can bias measurements of autoignition behavior and temperature-dependent reaction rates. This talk will delve into the interplay between facility-dependent compressible flow phenomena and reaction chemistry measurements, using recent measurements of the high-temperature oxidation chemistry of dimethylcyclohexane isomers – candidate components of next-generation, synthetic aviation fuels – as a case study. Optical measurements of ignition delay time and time-resolved species measurements, obtained using laser absorption spectroscopy, will be compared for the three isomers of interest. Techniques for overcoming facility-dependent non-idealities in shock tube experiments and implications for our understanding of dimethylcyclohexane oxidation reaction pathways will be discussed.
About the speaker
Dr. Alison Ferris is an Assistant Professor in the Department of Mechanical and Aerospace Engineering at Princeton University. Alison’s research interests include using shock waves and optical diagnostics to study the design, chemical synthesis, and reaction kinetics of fuels for use in current and next-generation energy and propulsion systems. Her current work focuses on accelerating the development of synthetic aviation fuels and developing kinetic mechanisms to describe stereoisomer-specific reaction pathways at low and intermediate temperatures. Before joining Princeton, she was a visiting research scientist at Technische Universität Darmstadt and a research scientist at Stanford University. Alison received her Ph.D. in Mechanical Engineering from Stanford University and an M.S. in Mechanical Engineering from the University of Wisconsin–Madison.
