题目：Sensing and Imaging Gas Dynamics in Extreme Environments: Rockets to Wildfires

时间：2021年3月19日 13:00

ZOOM会议号：985 3834 0253

会议室密码：302549

报告人：Dr. Mitchell Spearrin（加利福尼亚大学洛杉矶分校）

邀请人：蔡伟伟 特别研究员（叶轮机械研究所）

Biography

Dr. Spearrin is an Assistant Professor of Mechanical and Aerospace Engineering at the University of California Los Angeles (UCLA), where he directs the Laser Spectroscopy and Gas Dynamics Laboratory.  His research spans fundamental spectroscopic studies of collisional and radiative processes, optical diagnostic methods development, and experimental investigations of non-equilibrium flow physics and advanced propulsion and power technologies. Recent extensions of Dr. Spearrin’s research include biosensing for clinical breath analysis and environmental monitoring using novel optical methods. Dr. Spearrin has received the National Science Foundation CAREER Award, the Air Force Office of Scientific Research Young Investigator (YIP) Award, American Chemical Society New Investigator Award, and the NASA Early Career Faculty Award. Dr. Spearrin completed his Ph.D. in 2015 at Stanford University, working in the High Temperature Gas Dynamics Laboratory. Prior to his academic career, Dr. Spearrin worked for Pratt & Whitney Rocketdyne as a development and test engineer.

Abstract

Extreme environments typified by high temperatures and/or high pressures present unique engineering challenges. Energy and environmental flows at such extreme conditions often involve complex, temporally-dynamic and spatially-heterogenous domains governed by competing physics of fluid dynamics, heat transfer, and chemical kinetics that are poorly understood.  To improve understanding and predictive capability of these flow fields, quantitative sensing and imaging methods for temperature, species, and other fluid properties are needed. This talk examines the challenges and potential of laser spectroscopy for quantitative sensing in extreme environments with application to multi-physical and multi-scale thermo-fluid experiments. Basic and applied research areas are highlighted, including (1) photo-physics characterization of supercritical fluids, (2) development of a volumetric infrared laser absorption imaging technique, and (3) applied sensing and imaging in studies of advanced rocket propulsion and fire dynamics. Forward-looking research supported by emerging areas of photonics and data science are also discussed in the context of diverse engineering applications.