Title:

Ultrafast Laser-Based Atomic and Molecular Spectroscopy/Imaging for the Development of Next Generation Propulsion Systems

Speaker:

Dr. Sukesh Roy

Affiliation:

Spectral Energies

When:

Thursday, August 30, 2012 at 3:30:00 PM   Add to Calendar

Where:

Montgomery Knight Building, Room 317

Host:

Margaret Ojala
margaret.ojala@aerospace.gatech.edu

Abstract

Advanced measurement techniques that exploit lasers and optics have become well-established tools for characterizing combusting flows. Such noninvasive measurement approaches are often ideally suited for visualizing complex reacting flows and quantifying key chemical-species concentrations, temperature, and fluid-dynamic parameters. The fundamental information these techniques provide is essential for achieving a detailed understanding of the chemistry and physics of combustion processes. These measurement approaches enable fundamental understanding of combustion chemistry and unsteady dynamics in a variety of combustion and propulsion systems for model development and validation. Our research efforts span a range of activities, from theoretical modeling of new spectroscopic techniques to optical engineering and miniaturization for the transition to flight-line and in-flight testing. Although traditional combustion diagnostics based on continuous-wave and nanosecond-pulsed lasers continue to dominate fundamental combustion studies and applications in reacting flows, revolutionary advances in the science and engineering of ultrafast (picosecond- and femtosecond-pulsed) lasers are driving the enhancement of existing diagnostic techniques and enabling the development of new measurement approaches. The ultrashort pulses afforded by these new laser systems provide unprecedented temporal resolution for studies of chemical kinetics and dynamics, freedom from collisional-quenching effects, and tremendous peak powers for broad spectral coverage and nonlinear signal generation. The high pulse-repetition rates of ultrafast oscillators and amplifiers allow previously unachievable data acquisition bandwidths for the study of turbulence and combustion instabilities. The applications of ultrafast lasers for optical measurements in combusting flows and sprays, emphasizing recent achievements and future opportunities will be discussed.

Biography

Dr. Sukesh Roy, Senior Research Scientist and CEO of Spectral Energies LLC, specializes in the development and application of laser-based advanced diagnostic systems for propulsion applications. He leads the laser-based diagnostics team at SE. Dr. Roy received his Bachelor Degree in Mechanical Engineering from Bangladesh University of Engineering and Technology. He received his Ph.D. from Texas A&M University in 2002. While at Texas A&M, he received the Shibata Memorial Scholarship for academic excellence and leadership. Dr. Roy has extensive experience in developing and applying a number of linear and nonlinear optical-diagnostic techniques including: conventional CARS, triple-pump CARS, dual-pump dual-broadband CARS, picosecond CARS, femtosecond CARS, ballistic photon imaging, polarization spectroscopy, laser-induced incandescence, and laser-induced fluorescence in reacting flows. His work on the development of ultrafast CARS won the AIAA Dayton­ Cincinnati Section’s outstanding technical contribution award in 2008. Dr. Roy received two patents in 2006 for his innovative work on developing laser-based optical sensors for reacting flows. Dr. Roy was named one of Dayton’s 40 Super Achievers Under 40 in 2006 and received the Affiliate Societies Council Outstanding Engineers & Scientists Award in 2011 (awarded to the top engineers & scientists in the greater Dayton area). Dr. Roy has authored or co-authored over 80 peer-reviewed articles in archival journals as well as over 150 conference publications and presentations. In 2012 he was elected a Fellow of ASME and in 2008 he was elected an Associate Fellow of AIAA.