Abstract An experimental setup has been created to allow measurements of the properties of the gas phase, the liquid phase and the mixture in a pressure-atomised spray of water, in terms of both mean quantities and Reynolds stresses. This setup involves laser Doppler velocimetry for determining the velocity of either the gas or liquid phase, according to the parameters used, such as seeding or no-seeding of the ambient air, laser source power, or photo-multiplier gains, droplet tracking velocimetry for determining the velocity and characteristic size of the droplets, and a single optical probe for determining the mean volume fraction of the liquid, from which the liquid mean mass fraction and the mean density of the mixture are inferred. The experimental conditions, in particular in terms of liquid and gas Weber numbers, were chosen in a range for which the liquid phase turbulent kinetic energy should be mainly responsible for the liquid-jet primary break-up, these flow conditions lying within the second wind-induced atomization regime. Results reported herein are more specifically focused on the region ranging from 400 nozzle diameters to 800 nozzle diameters, where the liquid core is disrupted. They provide new information about the formation and properties of such pressure-atomised sprays, in particular in terms of the role played by the Reynolds stresses resulting from the slip velocity between the liquid and the gas. The mean slip velocity is directly related to the turbulent flux of liquid. Such information will be used in the future to develop new turbulence models since very limited experimental information is so far available for these terms.

中文翻译：

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压力雾化喷雾流动特性的实验分析

摘要 已经创建了一个实验装置来测量压力雾化水喷雾中气相、液相和混合物的特性，包括平均量和雷诺应力。此设置涉及激光多普勒测速仪，用于根据所使用的参数确定气相或液相的速度，例如环境空气的播种或不播种、激光源功率或光电倍增器增益、液滴跟踪测速法确定液滴的速度和特征尺寸，以及用于确定液体的平均体积分数的单个光学探针，从中推断液体的平均质量分数和混合物的平均密度。实验条件，特别是在液体和气体韦伯数方面，被选择在液相湍流动能应该主要负责液体射流初级分裂的范围内，这些流动条件位于第二风致雾化状态内。此处报告的结果更具体地集中在范围从 400 个喷嘴直径到 800 个喷嘴直径的区域，其中液体核心被破坏。它们提供了关于这种压力雾化喷雾的形成和性质的新信息，特别是在由液体和气体之间的滑移速度产生的雷诺应力所起的作用方面。平均滑移速度与液体的湍流通量直接相关。此类信息将在未来用于开发新的湍流模型，因为目前可用于这些术语的实验信息非常有限。