In this study, the atomization of an effervescent atomizer with an elliptical and circular orifice was investigated experimentally in the gaseous crossflow. The shadowgraph technique was used to visualize the near field of the spray atomization. To measure the spray penetration height in crossflow, image processing was performed on the shadowgraph images based on two different approaches: (i) a threshold analysis of average spray images and (ii) standard deviation images of spray. By comparing these two approaches, it is found that the penetration heights obtained from the standard deviation images were much higher since these images were able to capture small droplets more accurately. Moreover, based on the standard deviation images of spray, an empirical correlation for the spray penetration height was developed as a function of gas-liquid mass flowrate ratio, liquid-air momentum flux ratio, orifice aspect ratio, and downstream location. The laser diffraction technique was used to analyze the particle size of the aerated elliptical and aerated circular jets in a gaseous crossflow. For each orifice shape, the effect of gas-liquid ratio and downstream location on the Sauter mean diameter (SMD) was studied. The results show that the aerated circular jet penetrates higher into the gaseous crossflow than the aerated elliptical jet. Besides, the aerated circular jet in crossflow mainly generates smaller drop sizes compared to the aerated elliptical jet.

中文翻译：

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气体交叉流中的充气圆形和椭圆形液体射流

在这项研究中，对具有椭圆和圆形孔口的泡腾雾化器在气体错流中的雾化进行了实验研究。阴影图技术用于可视化喷雾雾化的近场。为了测量横流中的喷雾穿透高度，基于两种不同的方法对阴影图图像进行图像处理：（i）平均喷雾图像的阈值分析和（ii）喷雾的标准偏差图像。通过比较这两种方法，发现从标准偏差图像获得的穿透高度要高得多，因为这些图像能够更准确地捕获小液滴。此外，基于喷雾的标准差图像，喷雾穿透高度的经验相关性被开发为气液质量流量比、液气动量通量比、孔口纵横比和下游位置的函数。激光衍射技术用于分析气体错流中充气椭圆和充气圆形射流的粒径。对于每个孔口形状，研究了气液比和下游位置对 Sauter 平均直径 (SMD) 的影响。结果表明，加气圆形射流比加气椭圆射流更能穿透气体横流。此外，与加气椭圆射流相比，横流加气圆形射流主要产生较小的液滴尺寸。激光衍射技术用于分析气体错流中充气椭圆和充气圆形射流的粒径。对于每个孔口形状，研究了气液比和下游位置对 Sauter 平均直径 (SMD) 的影响。结果表明，加气圆形射流比加气椭圆射流更能穿透气体横流。此外，与加气椭圆射流相比，横流加气圆形射流主要产生较小的液滴尺寸。激光衍射技术用于分析气体错流中充气椭圆和充气圆形射流的粒径。对于每个孔口形状，研究了气液比和下游位置对 Sauter 平均直径 (SMD) 的影响。结果表明，加气圆形射流比加气椭圆射流更能穿透气体横流。此外，与加气椭圆射流相比，横流加气圆形射流主要产生较小的液滴尺寸。结果表明，加气圆形射流比加气椭圆射流更能穿透气体横流。此外，与加气椭圆射流相比，横流加气圆形射流主要产生较小的液滴尺寸。结果表明，加气圆形射流比加气椭圆射流更能穿透气体横流。此外，与加气椭圆射流相比，横流加气圆形射流主要产生较小的液滴尺寸。