4 ms·
A longer summary: the maximum height of a siphon pumping water, at sea level, predicted by barometric pressure is about 10m. But the tensile strength of water
by matthiasl 11y ago
A longer summary: the maximum height of a siphon pumping water, at sea level, predicted by barometric pressure is about 10m.
But the tensile strength of water is nonzero (a surprise to me) and that is enough to allow much higher siphons if you first remove dissolved gases from the water.
The paper speculates that several hundred metres may be possible, perhaps even more. The paper also describes an actual experiment where they showed that a 15 metre high siphon works in practice.
- venomsnake 11y agoWhat are the practical implications of higher siphons?
- johnm1019 11y agoIANA fluid dynamics expert, but it seems to me that for certain designs which move water by creating a lower pressure at some point inside of a pipe you've created a "siphon" in a general sense. If that's true, this could affect certain water pump and plumbing designs, albeit this degassing process may be prohibitively expensive.
- Gravityloss 11y agoClosed circulation central heating systems are degassed. Though, the water is hot there so boils much more easily. Maybe closed circulation cooling water systems...
- graeham 11y agoIts more than this - its that the model of balancing the weight of water with the vacuum pressure being the siphon limit is not correct. This paper shows an alternative model is more likely to be correct. It is that the water boils easily at low pressure, and that is the limit of siphon height. By careful preparation (degassing), boiling is prevented. Which here allows the column to be raised about 10m. A 'law of physics' has been modified. This is pretty cool!