Abstract: The atomized droplet size distribution of pressure swirl nozzle was obtained through Planar Laser Induced Fluorescence（PLIF）method in different liquid flows. The theoretical droplet size distribution was predicted using the three parameter maximum entropy model，which was constrained by average droplet size. The predictive distribution was fitted with the experimental result，and the general expression of generalized gamma function parameter α was obtained with the different liquid flows. Then，the characteristics and laws of droplet size distribution were summarized through the fitted model. The results show that the fitted model can well predict the number distribution and was not affected by small droplets. With the increase of liquid flow，droplet size distribution range becomes narrow，peak droplet size reduces linearly and the percentage of peak droplet size increases linearly.

Key words: pressure swirl nozzle, atomized droplet size, maximum entropy model

摘要： 利用激光片光荧光诱导技术（PLIF）测得不同液体流量下的压力旋流喷嘴雾化滴径分布，用平均粒径约束的三参数最大熵模型对雾化滴径分布进行预测。将理论预测分布与实验结果进行拟合，得到广义伽玛参数α随着液体流量变化的一般表达式。用拟合模型对粒径分布的特点和规律进行总结，结果表明：拟合模型能很好地预测粒径的数量分布，且不受小液滴的影响；随着液体流量的增加，液滴粒径分布范围逐渐变窄，峰值液滴粒径呈线性减小趋势，峰值液滴百分数呈线性增加趋势。

关键词: 液体喷雾, 喷雾滴径, 最大熵模型