The objective of the proposed research is to study the effect of ambient pressure on the ignition delay time and the burning time of boron agglomerates. In this investigation a probe- supported boron agglomerate mounted inside a high-pressure combustion chamber is ignited by a CO2 laser beam. The use of the laser ignition technique and high-pressure combustion chamber will permit the variation of the ambient pressure and oxidant mole fraction. Surface temperature measurements of the laser-ignited boron agglomerate during the ignition and combustion events will be carried out using a near-infrared, two-color pyrometer. In conjunction with the two-color pyrometer, a broadband radiometer is used to record the radiation emitted by the boron agglomerate. From the temporal outputs of the two-color pyrometer and the broadband radiometer, it is possible to determine the ignition temperature, the preignition delay time and the burning time of the boron agglomerate as function of ambient pressure and oxidant mole fraction. Boron slurries have a significant advantage over conventional jet fuels when evaluated on an energy-density basis. This project will provide experimental determination of boron particle agglomerate burning rates in the operating pressure range of one to 20 atm, typical of high-performance air- breathing engines.
