Wirtz pumps are really clever

Jonathan (from the video) wanted to answer a recuring question from the comments. Adding it to the pinned comment seemed to be the best approach. Here's Jonathan: Several comments ask: why not replace the spiral by wrapping the pipe round a cylinder instead? Some suggest this might actually be better than a spiral, but this isn't true. To see why, you first need to remember that air is much more compressible than water. Second, remember that, however the pipe is arranged, inside it are 'plugs' of water alternating with plugs of air. The first plug of air after the open end is under low pressure. The second is under higher pressure and so on. The innermost plug is under the highest pressure of all. As the air pressure increases, the volume of the plug decreases (this is Boyle's law). To maximise the pressure, ideally the plugs of water should be arranged like a set of left-hand brackets (((. Now, the circumference of the spiral decreases as we go towards the centre, and this fact helps to maintain the arrangement of plugs of water as the plugs of air shrink. The shrinking circumference makes up for the shrinking air plug length. End of Jonathan. That said, cylindrical pumps have been built and they work fine - they're just not optimal. The sponsor is Incogni: The first 100 people to use code SCIENCE at this link will get 60% off of: incogni.com/science

The fact that guy has it pumping 8 metres up his garden with no power other than the stream is incredible. I love this stuff.

I just love the fact he managed to get an entirely nature powered bog garden from a pump

You're always told to worry about airlocks as an apprentice plumber, but it's so unintuitive that I had to see it for myself to really appreciate how much force it can take to overcome an airlock. I installed a shower drain without enough fall, so when the house slightly moved in an earthquake, it started flowing backward. There was baaaaaarely enough room for an airlock to form, but once it formed it could hold a column of water like at least 5 times as high as the height of the hump that the airlock needed to overcome. That buoyant force is HUGE! Was worried about my repair, thinking I stuffed up the same job twice, when I got called back. Thankfully the tenants kid had just jammed multiple toothbrushes and pieces of fabric down the drain for whatever reason.

ONCE AGAIN, I tip my hat to Youtube. I was a horrible student in school. Even though I have a college degree I chose the path of least resistance in getting that degree. If I were in a class room and someone was trying to teach me the physics of a pump my eyes would just simply glaze over. Here, a combination of the comfort of my living room, the ability to re-watch portions of the video, the lack of stress from worrying about what was going to be on the test and the generally entertaining skills of the hosts and who he interviews results in genuine education. Needless to say, that education is also 100% free. Hats off to youtube. Thank you for your post.

It's proof of the kind of great man you are when you're able to admit the one and only mistake you've ever made in your life. Props to you! Cheers.

It's worth mentioning with air locking that air is more compressible than water, which means for the air to exert as much force on the next stage of water, the water behind it has to be exerting more pressure on the air than it would need to on just more water. In your three-stage demonstration, the water and air have time to find their natural equilibrium such that the pressure being exerted between each section of air and water equalises with the outside air. So the air inside is uncompressed, and when the water is forced to move again, the air will begin compression before it starts exerting enough force to start moving the next section of water at the same rate as the water behind it. It's kinda like pushing a block of wood with another block of wood via a spring... but also up and over a hill.

This is the real life equivalent of bug exploits in video games.

To make the first smaller model work, you could make the diameter gradually smaller along with the radius, so the inner rings have the same volume as the outer rings.

What's really cool is that you don't need any back flow prevention valves with these. The air lock stops the reverse flow of water if it stops. I work in irrigation sales and engineering and this stuff always amazes me. The physics of any pump system and how to create pressure is just cool stuff.

"the 2d fluid mechanisms explanations channel" is my favorite channel and i never miss an upload

This made me think of how some mechanical vacuum (and probably other) pumps are made, with two interlocking spirals, one static, and one spinning, trapping fluid towards the centre and out (or towards the edge and out, depending). They’re thin enough that they can be stacked and powered with the same motor, getting down to a pretty low pressure.

Hydra-Lock was a term an old boss of mine coined that would happen when torquing bolts when rebuilding transmissions. If there were any fluid in the blind holes, the seal of the part that was being torqued would sometimes fail due to a small amount of fluid being overlooked in the bottom of the hole not allowing matting surfaces to hold proper amounts of pressure.

Wonderful explanation!

The amount of questions this answered for me about water in my long range water pipes over the hills is priceless. :face-blue-smiling: Thanks Steve.

I was so pumped to watch this and then it vanished! I thought I was going crazy.

Just had a thought. You can totally sidestep the problems of a change in radius by wrapping the tubing around a cylinder instead of spiraling inward. It'd also let you have an arbitrarily huge number of windings.

I always wondered about pumping water with a water wheel. Thanks for the demo.

I did something similar in javascript and browser graphics and made a spiral that goes in faster to maintain a similar volume for the incompressable liquid and a shrinking volume for the gas. I was just thinking in terms of compressing gas and using the raised liquid to also compress in a separate mechanism gas as it returns I had in mind two grooved panels of something, perhaps plexiglass would work for your needs and a sheet of metal for the spiral. It seems to me like teflon coating might be ideal.

This pump reminds me of a water ram, which has always seemed to me like (almost) getting something for nothing.