The experimental observation and research on the internal flow of the flow focusing/blurring nozzle under different flow and structural parameters were carried out. The effects of the tube hole distance, the orifice structure parameters, and the gas or liquid velocity on the flow patterns were investigated. The results show that the flow patterns are significantly affected by tube hole distance, fluid velocity, and orifice diameter, but less affected by orifice length. Larger gas velocity, lower liquid velocity, smaller tube hole distance, and orifice diameter are beneficial to gas-liquid blending inside the nozzle. With the decrease of the liquid velocity, the tube hole distance and the orifice diameter, or the increase of the gas velocity, the liquid cone angle and liquid column diameter in the mixing zone decrease under the stable flow patterns. For unstable flow patterns, the maximum probability gray level of the two-phase flow images inside the nozzle decreases, and the concentration of gray probability distribution curve increases. In addition, the experimental images show that the flow focusing/blurring nozzle has different spray forms, which are closely related to the two-phase flow patterns inside the nozzle. Therefore, internal flow control measures such as controlling two-phase flow rates or tube hole distance are indispensable measures for good atomization quality.

中文翻译：

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聚焦/模糊喷嘴内流型及其对外喷雾影响的研究与分析

对流动聚焦/模糊喷嘴在不同流量和结构参数下的内部流动进行了实验观察和研究。研究了管孔距离、孔口结构参数和气体或液体速度对流动模式的影响。结果表明，流型受管孔距离、流体速度和孔口直径的影响显着，但受孔口长度的影响较小。较大的气速、较低的液速、较小的管孔距离和孔口直径有利于喷嘴内部的气液混合。随着液体流速、管孔距离和孔口直径的减小，或气体流速的增加，在稳定流型下混合区的液锥角和液柱直径减小。对于不稳定的流型，喷嘴内部两相流图像的最大概率灰度降低，灰度概率分布曲线的浓度增加。此外，实验图像表明流动聚焦/模糊喷嘴具有不同的喷雾形式，这与喷嘴内部的两相流型密切相关。因此，控制两相流量或管孔距离等内部流量控制措施是获得良好雾化质量不可缺少的措施。这与喷嘴内部的两相流型密切相关。因此，控制两相流量或管孔距离等内部流量控制措施是获得良好雾化质量不可缺少的措施。这与喷嘴内部的两相流型密切相关。因此，控制两相流量或管孔距离等内部流量控制措施是获得良好雾化质量不可缺少的措施。