Combustion of Supercritical Spray under High-Pressure and High-Temperature Conditions

The need to decrease our carbon footprint becomes more prevalent due to the increased awareness of its effect on climate change. Although electrification of the transportation sector is moving forward rapidly to increase efficiency through hybridization, combustion of hydrocarbons will continue to be the dominant choice for propulsion for many decades to come, especially the heavy duty, marine, and aviation applications.

This project will investigate a new combustion concept using supercritical fluids. It will advance and provide new knowledge pertaining to the applications of supercritical spray in combustion engines. The successful adoption of the proposed techniques can dramatically reduce the fuel consumption and pollutant emissions, benefiting the environment and energy security.

Additionally, this project will provide an excellent opportunity for integrating research and education. Graduate and undergraduate students, particularly from underrepresented and diversified groups, will be involved in the research. The research outcome from this project will help enrich three courses within the current curriculum.

The results can also be used to serve the engineering community and to motivate the younger generation (K-12 students) to pursue STEM majors in the future.

The hypothesis of this proposal is that supercritical spray combustion has significantly different mixing, ignition, combustion, and pollutant formation processes from conventional spray combustion and understanding the fundamentals can help achieve clean and efficient fuel combustion suitable for many emerging applications. The objective of this research is to experimentally demonstrate supercritical fuel combustion and quantify its impact on air-fuel mixing, ignition, combustion, and the production of pollutant emissions.

Supercritical spray combustion is a novel area that has not been well studied despite potential applications in next-generation compression-ignition engines and other combustion devices. Besides fundamental understanding of supercritical spray penetration, mixing, combustion, and pollutant formation, this study will have significant impact on the performance of future diesel engines.

Practically, the proposed research will have the potential to transform combustion engines with high fuel efficiency and ultra-low emissions. Fundamentally, the proposal research will fill the knowledge gap for spray combustion under extreme supercritical conditions.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.