Infrared Laser Absorption Spectroscopy in Extreme Environments

Abstract

Extreme environments characterized by high temperatures and/or high pressures present unique engineering challenges. Energy and environmental flows at such extreme conditions often involve complex, competing physics of fluid dynamics, heat transfer, and chemical kinetics that remain poorly understood. Advancing the understanding and predictive capability of such systems requires quantitative sensing methods for temperature, species concentration, and other thermofluid properties. 

This talk examines the challenges and opportunities of infrared laser spectroscopy for quantitative sensing in extreme environments. Both fundamental and applied research directions are highlighted, including (1) spectroscopic characterization of supercritical fluids, with particular emphasis on non-ideal high-pressure spectral phenomena such as line mixing effects and collision-induced absorption that strongly influence absorption lineshapes and signal interpretation, and (2) applied sensing in studies of advanced propulsion and energy systems up to 100 atm. These studies provide new insight into the photophysics of high-pressure fluids and establish a basis for quantitative measurements in regimes where spectroscopic databases and models remain incomplete.

Speaker

Prof. Chuyu Wei is an Assistant Professor of the Department of Mechanical Engineering at The University of Hong Kong (HKU). He received his BSc degree in Energy Engineering from Zhejiang University in 2015 and his PhD degree in Mechanical Engineering from the University of California, Los Angeles in 2020. Prior to joining HKU, he was a Postdoctoral Fellow at Stanford University. Prof. Wei’s research focuses on developing advanced laser-based diagnostics for next-generation energy and propulsion systems. His work integrates fundamental spectroscopy, optomechanical design, and advanced signal processing to create novel sensors for studying reacting flows and energy conversion processes. He has contributed to advances in infrared absorption sensing and imaging, scientific machine learning methods, hydrogen technologies, and the fundamental chemistry of alternative fuels.