EAGER: High-Speed Imaging Studies of Fuel-Spray Physics for Low-Temperature and Low-Density Ambient Conditions

University Of Alabama Tuscaloosa, Tuscaloosa AL

Investigators

Abstract

Increasingly, engines and power-generation systems are employing spray-based methods to introduce fuel into the combustion chamber. Sprays and spray combustion involve both physical processes (e.g., fuel vaporization, fuel-air mixing) and chemical processes (e.g., ignition, pollutant formation), neither of which are fully understood. In addition, vaporization and mixing set the initial conditions for combustion, and thus directly influence combustion efficiency and emissions. The purpose of this research is to investigate the physical processes involved in fuel sprays, particularly for conditions where fuel is sprayed into relatively low-temperature and low-density surroundings. Such conditions are characteristic of advanced engine combustion strategies, such as early direct-injection, which are increasingly being used to enhance efficiency and lower unwanted emissions. Research will be conducted in a spray chamber designed with extensive optical access, and through which an inert gas will flow continuously during experiments to allow fundamental studies of spray physics in the absence of the complicating effects of combustion. Studies will focus on penetration, dispersion, and turbulence of both the liquid and vapor phases of fuel sprays. These data will be sought using novel high-speed imaging techniques that will be developed as part of this project. The investigator will attempt to develop a technique to obtain both liquid- and vapor-phase information simultaneously using a single high-speed camera. Experimental results could lead to development of improved and more-flexible models that are likely to challenge conventional wisdom about fuel sprays. This project will have a direct and tangible effect on participation from underrepresented groups by providing support for the research activities and graduate education of an underrepresented student. In addition, the project will benefit undergraduate education in the Mechanical Engineering Department at The University of Alabama, as the investigator will incorporate the subject matter and results of the research into both the lecture and laboratory portions of an existing course in combustion engines. More broadly, the work will contribute to improvement of predictive spray and combustion models, which in turn will contribute to the development of cleaner and more-efficient combustion devices. This research, therefore, has the potential to impact the energy security and energy independence of this nation.