Liquid Atomization of a Radial Liquid Sheet Due to Transition to Turbulence.
Liquid Atomization of a Radial Liquid Sheet Due to Transition to Turbulence.
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由于过渡到湍流而导致径向液体层的液体雾化。
DOI：
10.1299/kikaib.64.1326
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
T. Azuma
中科院分区：
文献类型：
--
作者：
T. Wakimoto;T. Azuma
本文描述了径向变薄液膜的破碎和液滴形成的机理，它直接归因于层流向湍流的转变。水从圆管端部与圆盘平面构成的圆柱形薄间隙中流出，产生径向液膜流。液膜在圆盘上径向向外流动，从圆盘的周边边缘脱离，然后液体作为薄片向外流动。当雷诺数超过某一临界值时，液膜会发生突然的层流-湍流转变，导致液膜在极高雷诺数下穿孔和破裂。通过使用单脉冲闪光灯和钢照相机的放大摄影和使用多脉冲激光器和鼓形条纹照相机的高速摄影，公开了通过穿孔、韧带形成和液滴形成的破裂过程。这些照片清楚地表明，几十微米的液滴从液体片产生。给出了转捩引起雾化的流动条件。
This paper describes mechanisms of the breakup and the drop formation of a radially thinning liquid sheet, which is attributing directly to the transition from laminar to turbulent flow. A radial liquid film flow is generated by a water discharge from a thin cylindrical gap, which is constructed by the end of a circular pipe and the flat surface of a disk. The liquid film flows radially outward on the disk, detaching from the peripheral edge of the disk, and then the liquid flows outward as a sheet. Sudden laminar-turbulent transition occurs in the liquid sheet when the Reynolds number exceeds a critical value, resulting both in the perforation and the disintegration of the sheet under extremely high Reynolds number. The breakup process through perforation, ligament formation and drop formation is disclosed both by a zoom-in photography using a single pulse strobe and a steel camera and a high-speed photography using a multipulse laser and a drum streak camera. These photographs clearly show that droplets of a few tens micrometers are produced from the liquid sheet. Flow conditions for occurrence of atomization induced by the transition are also presented.