单液滴破碎流动机理试验研究

为了研究单液滴破碎内部流动机理,采用高速摄像机对不同流场分布中的液滴变形、破碎过程进行了捕获.基于试验中获得的现象,分析了液滴环境流场结构对液滴变形、破碎过程的影响,对液滴破碎流动机理进行了相关验证,并对其做了进一步完善.研究结果表明:气流的作用强度及液滴内、外部液体的流动特性决定了液滴不同破碎模式的发生;在气流作用下,在液滴的外部,液体沿气流方向的前、后驻点向垂直于气流方向的中心截面极点处运动;而在液滴的内部,为了克服液滴沿气流方向被压缩、沿垂直于气流方向伸展,在阻碍液滴变形内力的作用下,液体沿垂直于气流方向的上、下2极点向液滴中心位置处运动,使得液滴仍然保持球形.

Experimental Investigation on Flow Mechanism of Single Droplet Deformation and Breakage

In order to study the internal flow mechanism of single droplet breakup, the process of droplet deformation and breakup were obtained by using the high-speed cameras in different distribution of flow field. The influence of the droplet environment flow structure on droplet deformation and breakage process was analyzed based on the phenomena of experiment. The droplet breakup flow mechanism was verified and further perfected. The results show that the intensity of air flow and the flow characteristics of liquid droplet in both external and internal decide the droplet breakage modes. Under the effect of air flow, liquid flow from both forward and rear stationary points to the pole of center section across the flow outside of the droplet, while, inside of the droplet, from both upper and lower poles to the center of the droplet under the internal force against the droplet deformation, so that the droplets were not compressed along the flow and stretched across the flow, which remains the droplet spherical.