Applications include next-generation ultra-clean and efficient engines

Mitchell Spearrin, an assistant professor of mechanical and aerospace engineering at the UCLA Henry Samueli School of Engineering and Applied Science, has received a National Science Foundation CAREER award, the agency’s highest honor for faculty members at the start of their research and teaching careers.

The five-year, $550,000 grant will support his research using spectroscopy to understand the chemistry and physics of combustion at high pressures. Knowledge learned from the studies could be applied to the next-generation of ultra-clean and efficient engines in vehicles from cars, to airplanes and space-bound rockets. In particular for space-travel, such chemical propulsion systems must operate near performance limits, which means extremely high pressures. However, because conventional instrumentation is inadequate at these extremes, technology advancements in this area can be slow and expensive. New optical-based sensing methods could offer solutions to these challenges.

The grant will support building a new laser diagnostic tool for experimental studies of combustion under supercritical thermodynamic conditions – when the reacting fluid is neither in a liquid or gas phase, and therefore exhibits behavior that is difficult to model. To conduct these studies, Spearrin proposes developing new experimental methods in laser absorption spectroscopy – which measures what atoms and molecules are present by the signature wavelengths absorbed when the laser hits them. The method could also give insight into how they are behaving, and how they are reacting with each other under extreme temperatures and pressures. The research will also examine the chemistry of ignition under these conditions, and the resulting pollutant formation.

Spearrin joined UCLA in 2016. His research focuses on spectroscopy and optical sensors, including laser absorption and fluorescence, with experimental application to advanced propulsion, energy systems, and other dynamic flow fields. Prior to UCLA, Spearrin was a combustion devices development engineer at Pratt & Whitney Rocketdyne. He received his Ph.D. from Stanford University, working in the High Temperature Gas Dynamics Laboratory.