Combustion-generated soot particulates from land-based power sources pose a significant health risk and have been the subject of stringent regulations. The aircraft engine also contributes to atmospheric aerosol levels via high altitude soot emissions with impact on long term global climate change and ozone depletion. Mitigation of the negative aspects of soot formation will lead to improved well-being of individuals in society. In addition to the impact of the proposed research in combustion-related technologies, there will be a spillover in teaching and outreach activities. Graduate students will be trained and some aspects of the proposed work can be tackled by undergraduate students and possibly, upper level high school students. These activities are key components in the development of a diverse, globally competitive STEM (science, technology, engineering, and mathematics) workforce.
A fundamental understanding of soot formation in practical systems remains a daunting challenge and laboratory flames are the best setting in which to make progress. The proposed research has the realistic objective of examining the structure of laminar flames under conditions favorable to soot formation. It entails the characterization of temperature, gas species, including soot precursors and growth species, and soot properties including volume faction, aggregate morphology, and optical properties in flames. The proposal represents a comprehensive effort with potentially transformative impact in the context of the environmental footprint of combustion. Conditions are chosen so that the formation of soot is highly controlled by using suitable fuel-inert combinations to facilitate probing of the flame structure by both intrusive and nonintrusive techniques. The approach is both experimental and computational. Results of this research will be disseminated at technical meetings and in peer-reviewed articles. Furthermore, data sets will be made available on the web to allow convenient access to researchers for subsequent modeling.
