Australian Scientists Discover That You Can Build A Siphon Way Taller Than We Thought

If you’ve ever siphoned petrol from a tank, you’ll know that the height between the source and the destination of the liquid is important. But scientists have shown that the height limit of a siphon is much bigger than we thought.

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That’s cool.

“which operates quite happily at seal level.”

roflmao…

> maximum height of a siphon is usually thought to be defined by the atmospheric pressure of wherever you happen to be siphoning. … they carried out a set of experiments using degassed water instead of the usual stuff that comes out of your tap. They left water under a vacuum for more than three weeks, forcing large quantities of gas out of it — then they tested out how that affected the ability to create a taller siphon. Their results show that it’s possible to create a siphon that is 15m tall which operates quite happily at seal level. That’s because, according to the researchers, the degassing of the water prevents the cavitation from occurring: Without gas in the liquid, which can form bubbles as the pressure changes, the water’s essentially “stronger” and much harder to tear apart.

Brilliant. I didn’t see that coming.

mollwollfumble said:

> maximum height of a siphon is usually thought to be defined by the atmospheric pressure of wherever you happen to be siphoning. … they carried out a set of experiments using degassed water instead of the usual stuff that comes out of your tap. They left water under a vacuum for more than three weeks, forcing large quantities of gas out of it — then they tested out how that affected the ability to create a taller siphon. Their results show that it’s possible to create a siphon that is 15m tall which operates quite happily at seal level. That’s because, according to the researchers, the degassing of the water prevents the cavitation from occurring: Without gas in the liquid, which can form bubbles as the pressure changes, the water’s essentially “stronger” and much harder to tear apart.

Brilliant. I didn’t see that coming.

I haven’t read any of this but if someone at the bus shelter asked me this I’d tell them that it’s got bugger all to do with cavitation or gas in the fluid but everything to do with basic physics.

Peak Warming Man said:

mollwollfumble said:

> maximum height of a siphon is usually thought to be defined by the atmospheric pressure of wherever you happen to be siphoning. … they carried out a set of experiments using degassed water instead of the usual stuff that comes out of your tap. They left water under a vacuum for more than three weeks, forcing large quantities of gas out of it — then they tested out how that affected the ability to create a taller siphon. Their results show that it’s possible to create a siphon that is 15m tall which operates quite happily at seal level. That’s because, according to the researchers, the degassing of the water prevents the cavitation from occurring: Without gas in the liquid, which can form bubbles as the pressure changes, the water’s essentially “stronger” and much harder to tear apart.

Brilliant. I didn’t see that coming.

I haven’t read any of this but if someone at the bus shelter asked me this I’d tell them that it’s got bugger all to do with cavitation or gas in the fluid but everything to do with basic physics.

To me, cavitation and gas in the fluid IS basic physics. As opposed to say QM, GR, MHD, …
It’s the same phenomena that creates the danger of superheated water in a microwave.