虹吸管的高度限制

The height limit of a siphon.

作者信息

Boatwright A, Hughes S, Barry J

机构信息

Department of Chemistry, University of Leicester, Leicester LE1 7RH, U.K.

Department of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George St, Brisbane, Queensland 4000, Australia.

出版信息

Sci Rep. 2015 Dec 2;5:16790. doi: 10.1038/srep16790.

DOI:10.1038/srep16790

PMID:26628323

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4667279/

Abstract

The maximum height of a siphon is generally assumed to be dependent on barometric pressure-about 10 m at sea level. This limit arises because the pressure in a siphon above the upper reservoir level is below the ambient pressure, and when the height of a siphon approaches 10 m, the pressure at the crown of the siphon falls below the vapour pressure of water causing water to boil breaking the column. After breaking, the columns on either side are supported by differential pressure between ambient and the low-pressure region at the top of the siphon. Here we report an experiment of a siphon operating at sea level at a height of 15 m, well above 10 m. Prior degassing of the water prevented cavitation. This experiment provides conclusive evidence that siphons operate through gravity and molecular cohesion.

摘要

虹吸管的最大高度通常被认为取决于大气压力——在海平面约为10米。这个限制的出现是因为虹吸管中高于上部蓄水池水位的压力低于环境压力，当虹吸管的高度接近10米时，虹吸管顶部的压力会降至水的蒸气压以下，导致水沸腾，从而使水柱破裂。破裂后，两侧的水柱由环境压力与虹吸管顶部低压区域之间的压差支撑。在此，我们报告了一个在海平面高度15米（远高于10米）运行的虹吸管实验。预先对水进行脱气可防止气穴现象。该实验提供了确凿证据，证明虹吸管是通过重力和分子内聚力工作的。