The height limit of a siphon
نویسندگان
چکیده
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.
منابع مشابه
Corrigendum: The height limit of a siphon
We wish to acknowledge a related 1995 experiment performed by Andrew K Fletcher (http://inclinedbedtherapy. com), in which a 48 m length of 6 mm bore tubing, filled with degassed water was lifted 24 m vertical against Brixham Cliffs. A 50 ml bolus of coloured saline solution in the middle of the 48 m tubing was introduced prior to the tubing being raised to 24 metres vertical by its centre as a...
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