The Effects of Additives on High Speed Ignition and Combustion Characteristics of Storable Fuels

摘要

The report describes studies performed on mixing, ignition and combustion of high density fuels. Ignition and combustion augmentation of slurries using magnesium and lithium fluoride, respectively, is included. Experiments were conducted in a direct connect constant area combustor supplied by Mach 2 airstream at a pressure level of about 1 atmosphere covering a stagnation airstream temperature range from about 600 to 1600K. The results indicate that the autoignition limit for the lithium impregnated boron slurry appears to be about 1500K. It was found that within the piloting regime the boron slurry with and without the lithium fluoride involves four characteristic zones: no ignition, initial flame, staged burning, and propagating flame zone. These studies substantiate that the lithium fluoride mechanism of combustion enhancement involves chemical removal of the boron oxide barrier, rather than having a direct thermal effect. (Modified author abstract)