We demonstrate the optical diagnosis of air–liquid mixed sprays in the near-nozzle region using the supercontinuum (SC)-illumination long-working-distance microscopic imaging method, enabling the imaging of microdroplets, ligament structures, and cavities. In addition, SC-illumination long-working-distance microscopic imaging effectively suppresses speckles and reveals the ligament structures in the sprays more accurately. Finally, analysis of the droplet size distribution of the sprays under different air and liquid flow rates indicates that SC-illumination long-working-distance microscopic imaging offers several advantages for studying spray dynamics at the small structure level.

我们展示了使用超连续谱 (SC) 照明长工作距离显微成像方法对近喷嘴区域中的气液混合喷雾进行光学诊断，从而能够对微滴、韧带结构和腔体进行成像。此外，SC照明长工作距离显微成像有效抑制斑点，更准确地揭示喷雾中的韧带结构。最后，对不同空气和液体流速下喷雾的液滴尺寸分布的分析表明，SC 照明长工作距离显微成像为在小结构水平上研究喷雾动力学提供了几个优势。