There are two kinds of inverted siphon: box and round.
The upward movement of water in physics is a skill of hydraulic engineering.
(1) Pipeline? Drip inverted siphon flow description
"pipe?" Du Di describes the water flow brilliantly with overwhelming siphons: the nature of water, when it reaches a bend, must stay back, when it is full, push it forward, and the underground is parallel to control the height of the ground.
The author thinks that this paragraph is about the "water-based" of the pressure pipe flow, and the previous paragraph about the "water-based" of the free surface flow is about two parallel sections. "When you reach the bend, you must step back and push forward when it is full", which describes the phenomenon of channel water passing through the inverted siphon. When canal water flows into an inverted siphon that bends downward from one end, it must be filled with the inverted siphon first (the water flowing out from the other end can "go backwards and forwards"). When water flows through a building, there will be energy loss. Therefore, it is necessary to make necessary differences between the elevations of the water inlet and the water outlet of the inverted siphon, so that the elevation of the water outlet is lower than that of the water inlet and the water outlet is lower than that of the water inlet ("underground"), so that the water can pass smoothly. Otherwise, the channel water will flow under the control of inverted siphon, because the outlet end of inverted siphon is too high ("ground height").
(2) Inverted siphon in BC water supply pipeline in China and ancient Rome.
1975 to 198 1, in the excavation of Yangcheng site in Gaocheng Town, Dengfeng County, Henan Province, it was found that there was an urban pipeline water supply system in the late Warring States period, in which inverted siphon was actually applied. The whole water supply facility consists of water pipes, a control pit for controlling flow, a clarifier for settling sediment, a water storage pit and a water storage tank. There are eight water supply pipelines, arranged from high to low along the terrain, with a total length of several kilometers. The inner diameter of the water pipe is about 12.3 cm, and the water flow can reach 20 ~ 30 liters/second under submerged conditions.
The water pipe consists of straight pipe, three-way exhaust pipe, three-way water distribution pipe and four-way water control pipe, all of which are made of ceramic materials. The connection between the ceramic straight pipe and the exhaust pipe of the ceramic tee is shown in Figure 2- 14, and the shape of the ceramic tee is shown in Figure 2- 15. Most water pipes are laid in trenches dug by red sandstone. Groove depth1.2 ~ 2.0m.. ②
Around BC 180, there was a large urban aqueduct in Pagama, an ancient Greek city in Turkey. The water was transported from the source at an altitude of about 360 meters across two valleys to the castle, and the commanding height of the castle was only about 40 meters lower than the source. Among them, when there is an inverted siphon crossing the valley of 100 meters. (3) Vitruvius, a famous architect in ancient Rome, wrote an immortal masterpiece "Ten Books of Architecture" 2000 years ago, describing in detail the construction points of water pipe network at that time. For inverted siphon, Vitruwe also pointed out that in order to operate inverted siphon safely, it is necessary to build piers and exhaust risers. ①
(1) Do you want a tube? The calculation of river gradient in single dike and the description of hydraulic jump were first put forward by Mr. Yao Hanyuan in 1962.
② Henan Institute of Cultural Relics, Archaeological Department of Chinese History Museum, Wang Chenggang and Yangcheng in Dengfeng, Cultural Relics Publishing House, 1992, pp. 229-246.
(3) see チヤルズ? シンガ, first edition, translated by Hirata Hiroshi and Yagi Mulong, History of Technology-Medieval Mediterranean Civilization (Volume II), Zhu Mo Studies, pp. 58 1 ~ 583. Peter james's Ancient Inventions, Yan Kewei's Translation of Ancient Inventions of the World, World Knowledge Publishing House, 1999, p. 388. There is a kind of water pipe called inverted siphon, which is a kind of interchange hydraulic structure often used when the channel crosses roads, rivers or valleys. As early as more than 2000 years ago, China has been successfully applied. Like siphon, the facade is arched; The difference is that its bow bends downward. Moreover, although the principle of inverted siphon and siphon is the same, both rely on the water level difference between upstream and downstream, inverted siphon is more popular because it does not need to create a vacuum in the pipeline when it starts working.
Inverted siphon is mainly used in farmland water conservancy projects. When the channel crosses roads and rivers, aqueducts can be used. For example, Zhengbaiqu, which cited water mirrors in the Northern Song Dynasty, used aqueducts. Inverted siphon can also be used, for example, in the Southern Song Dynasty, it was used on the weir that quoted praise water. This kind of large inverted siphon is mostly mortar stones, and can also be connected with bamboo tubes. The application of inverted siphon in water conveyance channels is described and recorded in the poems of Du Fu, a poet in Tang Dynasty, and Wang Zhen, a scientist in Yuan Dynasty.