Optimization of combustion and plasma systems is important for a wide range of applications, from clean power generation to materials processing. The objective of this research is to significantly enhance the knowledge and understanding of non-equilibrium gas-phase chemistry in novel combustion and plasma systems through the development and use of a new laser spectroscopic approach known as ultrafast time/frequency domain coherent anti-Stokes Raman spectroscopy. This technique has the potential to overcome many of the shortcomings of conventional laser diagnostic approaches by enabling simultaneous characterization of temperature- and pressure-dependent energy transfer processes on a time scale that can resolve molecular collisions, vibrational and rotational energy levels within single and multiple species, as well as resonant and non-resonant time dynamics. Preliminary data indicate that these processes can be studied at measurement rates that are at least one hundred times faster than previous spectroscopic approaches, allowing transients in many practical devices to be resolved with unprecedented detail. The development and validation of a time-dependent theoretical model to capture the fundamental photophysics of ultrafast laser-matter interactions will take place in parallel with, and in many cases, guide the development of experimental innovations.
Broader Impact:
The broad impact of this research will be achieved, in part, by advancing the detailed understanding of gas-phase chemistry that is important for meeting current and future challenges in clean energy and manufacturing. Applications that benefit society include the development of chemical and molecular dynamics simulations of surface (or gas-solid) chemistry, high-pressure coal/biomass gasification, emissions reduction in combustion devices, catalytic upgrading and utilization of alternative fuels, electric discharges for boundary flow control, plasma-assisted ignition/combustion, plasma synthesis of nanotubes, and plasma deposition of silicon alloys for solar energy conversion. Strategies such as homogeneous charge compression ignition and oxy-fuel combustion, for example, invoke unconventional operating conditions, and experimental methods are required to help develop and validate models of chemical kinetics and energy transfer processes for a range of temperatures and pressures. The scientific knowledge gained through this work will be disseminated broadly through scholarly publications and collaboration with academia, industry, and national laboratories. The integrated research and education plan includes expansion of joint research and education activities through the Program for Women in Science and Engineering, as well as NSF sponsored Research Experiences for Undergraduates and Research Experiences for Teachers. Graduate students will gain experience in teaching and mentoring undergraduate students both in the laboratory and classroom, as well as inspiring k-12 students through a new program they have already piloted called "Engineering at the Speed of Light." The knowledge gained through this work will also be used for an advanced combustion course attended by graduate and undergraduate students, as well as expansion of curricula through the establishment of an Energy Systems minor in the College of Engineering.
