Abstract

The design and optimization of next-generation aerospace propulsion and combustion systems requires detailed knowledge of thermodynamic properties such as temperature and density. Turbulence, nonequilibrium, and high-pressure and temperature conditions relevant for modern combustors make for a challenging measurement environment that can exhibit significant spatial variation and fast temporal dynamics. Although conditions are challenging, experimental measurements are critical to validate and improve chemical kinetic and fluid dynamic models in order to design and test new vehicles and propulsion devices. Because the conditions of interest are harsh and dynamic, measurements using light/matter interaction are advantageous because they can be implemented nonintrusively. Beyond using light to study reacting flows, optical sensors that are sensitive to changes in flight parameters could be implemented in-flight to provide additional feedback for high-speed aircraft control systems. This seminar will discuss the development and implementation of laser-based measurements to study combustion and propulsion systems, including a scramjet engine. Hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps CARS) is applied for thermometry and species measurements and new work related to enhanced hydrocarbon species detection is discussed. Additionally, the development of optical emission spectroscopy sensors for hypersonic vehicle control is presented.

Speaker

Dr. Chloe Dedic

Dr. Chloe Dedic is an Associate Professor at the University of Virginia in the Department of Mechanical and Aerospace Engineering. Before starting at UVA in 2018, Dr. Dedic was a visiting researcher with the National Institute of Aerospace (NIA) at NASA Langley Research Center and obtained her PhD in mechanical engineering at Iowa State University in 2017. She is the recipient of a DARPA Young Faculty Award, a NASA Early Career Faculty Award, and the AFOSR Young Investigator Program. Dr. Dedic’s research interests are centered around the development and application of optical diagnostics and spectroscopy techniques to study reacting and nonequilibrium flows with the goal of furthering technologies related to clean and efficient energy utilization and the propulsion and aerodynamics of hypersonic vehicles.