Spray characterization of boron-loaded slurry fuels using high-speed imaging technique

Abstract

The characterization of atomized spray in terms of its structure, break-up, and droplet morphology is crucial to analyze an engine's performance. Therefore, in this study, the spray characteristics of boron-laden slurry fuels have been evaluated experimentally through a high-speed imaging technique. The rheological properties of the boron-loaded slurry fuels have been measured and their impact on the atomization behavior has been qualitatively analyzed. The spray cone angle, penetration length, sheet break-up length, ligament length, ligament diameter, and droplet diameter distribution are obtained by processing the time-sequences images. The experiments were performed at three atomizing air-to-liquid ratios (ALR). Spray characteristics of the fuel samples with various particle loadings (10%, 20%, and 30%) have been analyzed and compared with that of the pure Jet A-1. The obtained results were qualitatively analyzed with different non-dimensional parameters, such as Momentum flux ratio, Weber number, Ohensorge number, and Reynolds number. The results show that an increase in viscosity due to particle loading significantly affects the spray characteristics. However, a better atomization behavior of boron slurry fuel at higher ALR than low ALR, even with higher particle loading, has been observed. This is possibly due to the change in momentum flux ratio at higher atomizing air velocity.