论文标题
插孔涡流诱导的空气核心流量结构的研究
Study of air-core vortical flow structure induced by a plughole vortex
论文作者
论文摘要
本文描述了一项研究插孔涡流的产生及其在固定矩形坦克水排水期间在排水管中的后果。参数检查了流管上方的临界和最小水深处，在该排水管的入口上开始开发表面倾角以进行各种直径的排水管。这项研究探讨了插孔涡流引起的以下自然现象。 （i）插孔涡流最初会导致表面倾角向排水管的入口发展，并且随着表面倾角接近排水管的入口，它会产生液滴形的气泡。 （ii）独特的气泡转化，即从液滴形到甜甜圈形气泡环，就在液滴形气泡与表面倾角的分离之后发生。 （iii）甜甜圈形气泡环用排水管流动，最初导致排水管中的气泡流动。 （iv）随着排水管入口上方的水头减小，液滴形的气泡尺寸增加，因此，气泡环的尺寸增加并导致排水管中的sl液流动。 （v）随着sl的组合，排水的流动最终会在排水管中流动。由于气泡形成过程，观察到诸如瞬时嘶嘶声和气泡水槽排水之类的声音。研究了气泡的形状和大小的时间变化。在0.45至0.6的范围内，发现气泡直径与气泡长度的比率与水深与排水管直径的比率成正比。在数值上模拟了几个排水案例，以观察这些天然现象的物理。使用Vortex Core方法对插孔引起的涡旋的形状和大小已被可视化和分析。
This paper describes a study of the generation of a plughole vortex and its consequences in a drainpipe during drainage of water from a stationary rectangular tank. The critical and minimum depths of water above the inlet of the drainpipe, where a surface dip starts to develop for drainpipes of various diameters, were examined parametrically. This study explored the following naturally occurring phenomena arising from a plughole vortex. (i) A plughole vortex initially causes a surface dip to develop towards the inlet of the drainpipe and as the surface dip approaches the inlet of the drainpipe it creates a droplet-shaped air bubble. (ii) A unique bubble transformation, i.e., from a droplet-shaped to a donut-shaped bubble ring, occurs just after the separation of the droplet-shaped air bubble from the surface dip. (iii) The donut-shaped bubble ring flows with the drain water and initially causes bubbly flow in the drainpipe. (iv) As the water head above the inlet of the drainpipe decreases, the droplet-shaped bubble size increases, and consequently, the bubble ring size increases and causes slug flow in the drainpipe. (v) As the slugs combine, the flow of the draining water eventually becomes annular flow in the drainpipe. Sounds, such as that of instantaneous fizz and bubble sink draining, were observed to be produced as a result of the bubble formation process. Temporal changes in the shape and size of the air bubbles were studied. Within the range of 0.45 to 0.6, the ratio of the bubble diameter to the bubble length was found to be linearly proportional to the ratio of the water depth to the diameter of the drainpipe. Several drainage cases were simulated numerically to observe the physics of these naturally occurring phenomena. The shapes and sizes of the vortices induced by plugholes have been visualised and analysed using the vortex core method.
