Abstract The twin-fluid atomizer employing the cross-stream mixing arrangement for air and liquid prior to the orifice exit is investigated with a scaled-up size transparent injector. Simplistic optical flow diagnostics techniques (Mie scatter and high-speed LED-backlit imaging) were employed to characterize the effect of operating parameters on internal two-phase flow development and the external spray characteristics of a transparent flow blurring (FB) injector of 6 mm exit orifice diameter. Two successive Mie scattering images of the spray are utilized for the PIV analysis along with mathematical manipulation of Mie scatter intensity profile at any axial location to contrast the spray quality for two different operating conditions. Derived droplet velocity field from the PIV algorithm is used to show the spray development confines to the near field region of five diameters downstream of the nozzle exit. The experiments were carried out for different values of air to liquid ratio (ALR) ranging from 1 to 2.5 with an increment of 0.25 for 5 different Liquid flow rates (LFR). Results indicate that the internal two-phase flow mixing characteristics of FB injector dictates the spray formation and its quality. This internal two-phase flow mixing is responsible for the jet break up in liquid tube itself leading to finely atomized spray. Laplace number defined as a product of Euler and Weber number is proposed as an injector performance number as it uniquely links to the spray quality. The impact of operating parameters such as ALR on relative atomization efficiency and spray quality in the near field is characterized.

中文翻译：

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流动模糊雾化实验研究

摘要 采用放大尺寸的透明喷射器研究了在孔口出口前采用交叉流混合布置的空气和液体的双流体雾化器。采用简单的光流诊断技术（Mie 散射和高速 LED 背光成像）来表征操作参数对内部两相流发展的影响以及 6 毫米透明流模糊 (FB) 喷射器的外部喷雾特性出口孔径。喷雾的两个连续 Mie 散射图像用于 PIV 分析以及任何轴向位置的 Mie 散射强度分布的数学处理，以对比两种不同操作条件下的喷雾质量。从 PIV 算法导出的液滴速度场用于显示喷雾发展仅限于喷嘴出口下游五个直径的近场区域。对 1 到 2.5 范围内的不同气液比 (ALR) 值进行了实验，对于 5 种不同的液体流速 (LFR)，增量为 0.25。结果表明，FB 喷射器的内部两相流混合特性决定了喷雾的形成及其质量。这种内部两相流混合导致射流在液体管本身中破裂，从而导致细雾化喷雾。拉普拉斯数定义为欧拉和韦伯数的乘积，被提议作为喷射器性能数，因为它与喷雾质量唯一相关。