Improved Two-Phase Model for JP-8 and Alternative Fuels

The Air Force has identified a number of key issues for combustion systems as attention turns towards “logistic fuel replacements” (e.g., JP-8 in the near term; Fischer-Tropsch derived fuels from coal, bio-oils or other feedstocks in the mid term blended with JP-8; and/or bio-derived fuels such as fatty acid methyl ester—FAME; or hydroprocessed vegetable oils-HVO in the longer term). In addition, DARPA’s biojet program can be looked to for guidance on specific direction in future fuels for the near and long term. The proposed project will conduct experiments directed at determining the role of fuel type on atomization, evaporation, and combustion behavior of such fuels. In parallel, models associated with the atomization and evaporation phenomenon will be assembled and evaluated for their ability to predict the measured behavior. Where possible, these models will be improved so that they can better capture the effect of fuel type on the characteristics which are key to performance of spray based systems. The assembled package of improved models will be standalone or integratable into CFD environments. The high quality, detailed data set obtained can be also used to validate third party modeling approaches as well. BENEFIT: The proposed experiments will provide important fundamental data on atomization, evaporation, and combustion of sprays for various alternative fuels as injected by different atomizer types in different environments. This information will be of interest to commercial engine and injector manufacturers as they improve fuel flexibility of their products. Industrial partners can also utilize the information obtained from the experiments. The improved models developed and validated will be of interest to these same end users as a means to help them improve existing products and develop new ones.