Title:

Laser Diagnostics in Propulsion and Power

Speaker:

Prof. Adam Steinberg

Affiliation:

Aerospace Engineering, Georgia Tech

When:

Thursday, January 27, 2022 at 11:00:00 AM   Add to Calendar

Where:

MRDC 4211 or MS Teams: https://tinyurl.com/4mev3wjr Building

Host:

Ellen Mazumdar
ellen.mazumdar@gatech.edu

Abstract

Laser-based measurement techniques help reveal the inner workings of complicated physical systems -- such as aerospace propulsion and power generation engines -- allowing us to better understand, predict, and engineer their behavior. After a brief overview of some relevant laser diagnostics and their applications, this talk will delve into two recent developments in greater detail. Firstly, we will discuss the use of terahertz time domain spectroscopy (THz-TDS) for making measurements inside of Hall thrusters, which are an important propulsion technology for future long-distance space missions. We present a novel Bayesian framework for simultaneously deducing the electron number density and collision frequency, and demonstrate its use in plasmas bounded by Hall thruster wall material. These measurements open the possibility for explaining key physics affecting Hall thruster performance and durability. Secondly, we will discuss the use of tomographic particle image velocimetry (TPIV) and formaldehyde planar laser induced fluorescence (PLIF) to investigate flame-scale turbulence production and cross-scale kinetic energy transfer in a model gas turbine swirl combustor. We provide the first experimental measurement of mean up-scale kinetic energy transfer (back-scatter) within the flame, which is counter to the forward cascade hypothesis underpinning popular (purely dissipative) turbulence closure models.

Biography

Adam Steinberg is an Associate Professor in the School of Aerospace Engineering at Georgia Tech and the Director of the Ben T. Zinn Combustion Lab. Prior to joining Tech, he held a Canada Research Chair as an Associate Professor at the University of Toronto Institute for Aerospace Studies and served as a Research Associate at the German Aerospace Center. His research focuses on overcoming the scientific and technical barriers facing future aerospace propulsion and energy conversion devices. Working closely with government and industry, his research group develops and applies advanced laser-based measurement techniques that help unravel the coupled thermal, fluid, and chemical process occurring in these devices. Topics of interest include light/matter interactions, turbulence, combustion, gas turbine engines, chemical rockets, electric space propulsion, high-speed flows, data analysis, and experiment/simulation coupling. Dr. Steinberg is an Associate Fellow of the AIAA and Associate Editor of Combustion and Flame.