Partner User Proposal Abstract
Fuel Spray Research at the 1-BM Beamline of the APS (PUP-3)
High-pressure, high-speed sprays are an essential technology in many industrial and consumer applications, including fuel injection, inkjet printers, liquid-jet cutting and cleaning systems. The importance of detailed gasoline and diesel-fuel spray analysis is well recognized as vital information needed to increase the combustion efficiency and reduce the emission of pollutants of internal-combustion engines. High-pressure sprays are optically dense or the liquid droplets generated by the sprays scatter light so strongly that the detailed structure of the sprays cannot be resolved by conventional optical means. This is especially true in the region near the injection nozzle, which is often the region of greatest interest in understanding the structure of the spray. Other challenges arise from the transient nature of the sprays, frequently requiring images on µs time scales. The lack of quantitative, time-resolved analyses on the structure and dynamics of sprays in the near-nozzle region limits the accuracy of spray modeling and creates obstacles to improving spray technology.
X-rays are highly penetrative in materials composed of extremely dense droplets composed of low-Z materials due to the intrinsically low interaction cross section. This makes x-rays a suitable tool for fuel-spray studies designed to overcome the limitations of visible light. With the advent of synchrotron radiation sources, extremely brilliant monochromatic x-ray beams are now available, we propose to reveal many transient characteristics of fuel sprays quantitatively and unambiguously that were never previously known and/or that could not be measured by any other means. More specifically, the proposed research will use time-resolved x-radiography and tomography at the APS 1-BM beamline to study the high-pressure fuel sprays. This synchrotron experimental work will be complemented by fluid dynamics simulations that also included in the scope of the proposal.
