Principles of Siphons
Principles of Siphons
复制标题
虹吸管原理
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
R. Garrett
中科院分区：
文献类型：
--
作者：
R. Garrett
一个简单的虹吸管将水上升到顶部，然后在较低的高度排出。当水流经虹吸管时，压力和高度产生的能量要么因管道摩擦而损失，要么转化为速度能。对于大多数实际的虹吸管，50%到75%的可用于驱动流动的仰角能量将转换为速度能量。
A simple siphon raises water over a crest and discharges it at a lower level. As water flows through a siphon, energy due to pressure and elevation is either lost to pipe friction or converted to velocity energy. For most practical siphons, between 50 and 75% of the elevation energy available to drive flow will be converted to velocity energy.
A standpipe covered with a dome will begin to siphon when the standpipe flows full. During siphoning, the flow rate may be several times higher than the flow through an uncovered standpipe of the same size. Furthermore, the covered standpipe can be designed to lower the water level to a point below the top of the standpipe before siphoning is allowed to stop.
Flow into the covered standpipe can be drawn from the bottom of the reservoir by extending the skirt of the dome. A vent tube allows easy adjustment of the elevation at which air enters the dome and siphoning stops. Flow rate and water level required to start the siphon depend on the pipe diameter. Some flow through the standpipe will occur before siphoning begins. Flow into the reservoir must be greater than the flow required to start siphoning. Maximum flow through the standpipe during siphoning depends on pipe diameter and the elevation energy driving the flow.
Adding a trap to the outlet of the covered standpipe eliminates the leakage flow prior to the start of siphoning. When air bubbles out the trap at the end of the standpipe, pressure inside the dome is released suddenly allowing the water level to jump above the critical level needed to start siphoning. For reliable operation, the crest height of the trap should be about equal to one diameter of the standpipe. The vent tube opening must be below the top of the standpipe to prevent premature overflow of the standpipe. Because a trapped outlet siphon has no minimum flow limit, the standpipe can be sized to carry any maximum flow.
While the trapped outlet siphon eliminates low rate leakage flow prior to the onset of siphoning, the height differential between the start and stop of siphoning cannot be as small or as easily adjusted as with a covered standpipe without a trap. The simple siphon is convenient for some applications, but it does not lend itself to automatic cycling operation. The choice depends on the needs of the situation.