Jet fuels with various properties are desirable for different operational or environmental advantages, necessitating fuel-flexible technology. For example, JP-5 (A-3) and alternative jet-fuels with high flash points are favored for safe handling and other advantages. The study investigates the effects of fuel properties on the near-field spray characteristics of the relatively viscous A-3 and a more viscous alternative fuel blend (C-3) compared to the baseline fuel—Jet A (A-2) with the least viscosity, using the relatively novel twin-fluid flow blurring (FB) injection. Prior studies have acquired fine FB atomization with high viscosity tolerance compared to conventional jet-based injectors, where atomization is suppressed by high viscosity. The study aims to further quantify the FB fuel flexibility using shadowgraph and particle image velocimetry to potentially enable effective utilization of the desired jet fuels. Results show that the FB injection achieved fine sprays immediately at the injector exit rather than typical jets by conventional atomization. Nearly the same atomization completion length, within 4 D downstream the injector exit with the diameter D of 1.5 mm, was acquired for all three fuels regardless of the varying properties. Compared to A-2, the final droplets of the viscous A-3 are only 6% larger and the most-viscous C-3 are only 10% larger. It is also observed that the density of fuel affects the droplet travel distance from the injector exit to a downstream location before achieving a terminal or peak velocity. Droplet size distribution, velocity distribution, and Weber number estimate consistently reveal more turbulent bag breakup mode at the spray periphery resulting in smaller droplets, compared to the oscillatory mode yielding larger ones in the center.

具有各种特性的喷气燃料具有不同的操作或环境优势，因此需要燃料灵活的技术。例如，JP-5 (A-3) 和具有高闪点的替代喷气燃料因其安全处理和其他优点而受到青睐。该研究调查了燃料特性对相对粘性 A-3 和粘性更高的替代燃料混合物 (C-3) 的近场喷雾特性的影响，与基线燃料 - Jet A (A-2) 相比，粘度，使用相对新颖的双流体流动模糊 (FB) 注射。与传统的基于喷射的喷射器相比，先前的研究已经获得了具有高粘度耐受性的精细 FB 雾化，其中雾化受到高粘度的抑制。该研究旨在使用阴影图和粒子图像测速法进一步量化 FB 燃料的灵活性，以潜在地实现所需喷气燃料的有效利用。结果表明，FB 喷射在喷射器出口处立即实现了精细喷雾，而不是传统雾化的典型射流。几乎相同的雾化完成长度，在4以内d下游与直径的喷射器出口d为1.5毫米，被收购所有三个燃料而不管变化的特性的。与 A-2 相比，粘性 A-3 的最终液滴仅大 6%，而最具粘性的 C-3 仅大 10%。还观察到，在达到终端或峰值速度之前，燃料密度影响从喷射器出口到下游位置的液滴行进距离。与在中心产生较大液滴的振荡模式相比，液滴尺寸分布、速度分布和韦伯数估计一致地揭示了在喷雾周边更多的湍流袋破裂模式导致较小的液滴。