My suggestion would be lubrication of the moving parts. Using something like dry Teflon lubricant, graphite, or even a pencil I imagine can make a difference when the air pressure drops even more. Also, real internal combustion engines use a weighted flywheel to smooth themselves out and keep their rotational inertia going between ignition strokes, since in a normal single-cylinder four-stroke engine, there's quite a lot of time between ignition because the piston has to go up and down three more times until the next power stroke. When the air engine slows down and starts oscillating, it's likely because it loses inertia and needs something to keep it spinning in one direction, not to mention smoothing it out. Something heavier than a carbon fiber propeller like an aluminum disc.
That would also make use of the extra energy the engine has in the beginning when the pressure is higher than the equilibrium point, allowing it to speed up!
Awesome build! It’s really cool to see the ways you were still able to squeeze higher efficiencies from the motor even after all of the iterative work you’d done to improve it in the previous video!
the solution to your issue is to add more cylinders :3 being able to apply at different stroke phases will enhance efficiency as the blade wont be accelerating and slowing down as often (which is how the change in direction occurs), and the resulting increase in total diaphragm area will allow it to run better at lower pressures. Have you considered adding some intertial mass (flywheel) to the system to also help balance out the power application of the motor to stop the accel/decell issues it has?
Wonderful! You could add a floater into the tank to that automatically blocks the outlet as soon as the water reaches the top. That way you don't have to worry about flooding the engine.
Came to the comments knowing someone else thought of this too! Great job, Tom! Always enjoy watching you build and enjoy whatever it is you are building!
I had an idea for a practical use of this: toilet flush powered air circulation. The tank would need to be made specifically for this task, but after flushing, while it fills up it would power a fan.
No need to block the output, he needs to add an air tank to the output, connect them with a one-way valve, and make a swimmer to dump the water out. The valve+tank setup will keep the air pressure going while the tank empties and refills.
Fun fact, having an open system like that with a tank on the loft, is actually how you pressurized the central heating system in houses back in the day 😄 Here in Denmark they used to measure the water pressure in the system in mVs (meter vand søjle) meaning “meter water height” I suppose. Basically one meter is equal to .1 bar of pressure :)
And yes, I learned the hard way that was how it worked. Because yes, when the house had been connected to the municipal water system, there was a valve through which you could repressurize the central heating system, and no, the open tank up in the second floor wasn't removed... And no, I didn't overfill the system directly, I did follow the pressure gage. But the heater got the water in the system too hot because of some wrong settings. I did get all the warm water cleared before it had a chance to get soaked in anywhere. Luckily. But that was still quite dramatic.
Today they will burn coal, in order to spin a steam engine at high pressure, then run that energy in form of electricity over miles upon miles of copper power lines into your house to charge you for it. Not at all wasteful, not ever heard of energy transfer loss of (80%+!). When instead you could just burn that coal right at your home from wood on your property to minimize cost and waste (SHhhSHSHSHhhhhhh) dont tell anyone you'll get shad0wb4nn3d! Well, or in this case, instead of burning coal, just carry some tanks of water upstairs every day to run a small dynamo to charge the basic of electronics. Or collect some rain water from the roof and channel it into the system.
You can do the same thing with running water for infinite compressed air using something called a trompe. Mines and other industries that use a lot of compressed air have used this technique for creating compressed air for nearly as long as the need for compressed air has existed. All you need is plenty of water and a change in elevation. Also worth noting is that you get more air pressure from a trompe then you do from a static column of water thanks to the inertia of the water as it falls similar to how a ramp pump provides more pressure out than the input pressure.
I was about to suggest a trompe as well--that way, there's no need to cut the water supply to avoid drowning the engine, since the trompe draws in outside air as long as the water keeps flowing.
yes, but it requires a continuous flow of water..a LOT of water. Works great if you have a stream or something doing nothing anyway, a lot less great if you have to move all that water back to the top when your done.
I always think those are so cool. They are a great combination of a lot of important concepts. The first person to see one of those systems had to be totally amazed.
I don't know exactly what it is, but I could watch your air engines puffin away for HOURS without getting bored! This must be the most wholesome and entertaining piece of tech I ever saw coming out of a 3d printer and I am kinda sad, that I lack the technical knowhow and equipment to do stuff like that. Thank god for people like you who can scratch that itch for me anyway :D
My dad told me a few years ago that my grandpa actually used air engines to run a pump when he was working which I find fascinating. I had first heard of these when I was going to school for drafting, I had built a design for one and played around with a 3d print as well. At that time I didn't think that it was anything more than just a representation of what could be done if you play around with physics but since then I have been absolutely obsessed with these
Not to take credit away from Tom, because it does looks very clean and it is was for sure an interesting video! But you should look up "DIY Perks" for some amazing projects
Please be careful with acrylic pressure tanks. They tend to fail catastrophically. Not a problem at those low pressures but once you go above that, add a layer of translucent tape around it that keeps the acrylic parts from flying everywhere in case of failure.
Pressure vessels are typically designed to bend and leak, rather than break at the strength of the material. This one is probably done wrong, so yeah, failure mode is an important consideration.
You don't need a larger ports to reduce you're losses from the water flowing through the tube. If you put an adapter on the inlet to the pressure chamber and the outlet of the upstairs tank that adapts to a larger diameter tube, you will increase your flow rate even without changing threaded port size. This is because most of your losses are not coming from the simple restriction of the flow cross section, but rather from the friction against the wall of the tube. In fact, in hydraulic engineering (ie engineering of any fluid conveyance system) the losses due to flow restricting components are referred to as "minor" head loss while those due to wall friction are "major" head loss because of how much higher they usually are. If you look at the equation for major head loss you'll see it is the Darcy Friction Factor (usually given the symbol f with subscript D) multiplied by the tube or pipe length, divided by the hydraulic diameter (just the inner diameter in the case of circular cross sections). This means that you can reduce your major head loss significantly by simply adapting to a larger tube diameter, and then just accept that the minor head losses from the comparatively undersized ports at either end.
The flow rate for given pressure gradient during laminar flow actually scales as the *4th power* of the diameter. So increase the diameter by a factor 2, gain 16x the flow (or increase by only 20% to double it, roughly).
@@landsgevaer last i checked the formula for major headloss was proportional to D^-1 not D^-4. could you elaborate on what model that predicts a D^-4 relationship?
@@maxk4324 Laminar flow in a tube. Speed goes like diameter squared since it has a parabolic velocity profile, multiplied by cross sectional area that also goes like diameter squared. en.m.wikipedia.org/wiki/Hagen%E2%80%93Poiseuille_equation Initially I thought that turbilent flow might scale with a lower power, but linear with diameter seems weird since then the velocity in the center of the tube would need to decrease with diameter, given that flow scales with area. Not sure what you mean with this major head thingy, so maybe you can give your reference too...? 😉
This is like a fluid over air cylinder in automation for industry. They do work really good at lower pressures. I hardly had any problems with them in my previous encounters as a maintenance employee at a large automotive plant.
The flow rate is limited much more by friction losses in the long tube than by the size of the fittings. If you printed some adapters and replaced the tube with one that has a larger diameter, the pressure probably would stay at a value much closer to 0.6 bar.
So, interestingly, you have definite starting and ending quantities of air, and you can easily (😟) count the number of rotations. This will tell you exactly how much air is spent on each rotation which would be very interesting to compare to the volume of your cylinder. It would tell you how much air leaks on every stroke. It seems like that number would be pretty small.
Except he doesn't have a "cylinder", it's the weird flying saucer shaped area above the diaphragm and that doesn't get filled with air at the inlet pressure since the valve only opens for a short time.
I wonder if you could get more air volume by putting a T fitting and a schrader valve below the pressure gauge, then pump the water back up to the reservoir with a bike pump by pumping air into the tank?
@@mjolnirswrath23 Energy is conferred to the motor by removing air from the system (allowing more water to run down from above, transferring the water's gravitational potential energy into air pressure, and from there into kinetic energy in the motor); in a closed loop the air trying to go back into the tank would be fighting water pressure, which would stop the system (or, alternate explanation, if the air is allowed back into the tank it would prevent water from flowing down, stopping more energy from making it to the motor, the system would be at equilibrium and no movement would happen). Similarly, collecting the water from hydrogen combustion is all well and good, but energy still needs to be re-introduced into the water to separate it back into oxygen and hydrogen before it's fuel again. Unfortunately there's no such thing as infinite energy, it has to come from somewhere.
It's amazing how well the engine self-regulates, slower RPMs meaning it consumes less air per second and lets the pressure build back up. Would a heavier flywheel help it avoid stalling at very low RPM, or just keep the RPM high until it starves itself of air?
A flywheel only helps at smoothing the motion between power strokes, it is not needed to reach high speeds, hence why he didnt use it previously. It would have definitely been useful here to maintain a smoother rotation tho
I think a heavy flywheel would be helpful. Think about those old hit-and-miss engines. They had massive flywheels and they could operate at low RPMs, like 250 RPMs. There are accelerations and decelerations of the piston, rod, and crankshaft in every rotation. A heavy flywheel would stabilize the accelerations and deccelerations. Which would increase the efficiency. I don't think that the propeller has enough weight. I would try something like a wheel from a push lawnmower or an aluminum pulley for a belt drive about 6 inches in diameter.
Thought I might mention that as I understand it, most of the water pressure loss is in the plastic pipe, and a bit in the fittings, replacing the pipe alone should significantly increase the water flow rate. Besides that loved your enthusiasm to discover something new. Wonderful stuff!
You need to design an Air tank that maintains pressure at a constant, without the weight of water. Some sort of self collapsing tank that inflates with the air pressure and slowly reduces the inner space with an equal opposing force. Maintaining a steady slow collapse and low weight, would be the key.
Here is an idea,instead of having 2 pressure chambers,make it 3,one above the other to provide water,2nd one to provide pressure,and you can make a hole up on the half of the cylinder for water drainage system.So chamber number 3 will collect water,it would be intresting to put it on some sort of moving platform where chambers 1 and 3 will switch places constantly as one drains and other provides water as needed.But you will have to constantly rotate the chamber number 2 because of the holes for drainage/providing.This all can be solved with 2 electromotors one for moving the platform of chambers up and down,and other to rotate/flip 180 degress the middle chamber.I think with this system in place it could seriously provide some close to similar perpetual motion(Mind that you need electricity for that 2 electro motors).Just a thought..
This project reminds me of a TH-cam video I once watched, which discussed a unique power source for pneumatic tools that were needed for mining in a remote town somewhere in Canada. It used an cylindrical bell-like structure (made of iron or steel, if I remember correctly), which had a fitting at the top, through which pressurized air could be fed into pipes and hoses that attached to the various tools that were used (drills, power-hammers, conveyer belts, etc). The “mouth” of the bell was lowered into a deep pool in a nearby river, which trapped the air in the bell below the surface of the water, so that the air in the bell was compressed by the surrounding water. Then, as I understand it, they brought water, via an aqueduct, to a fluke that ended at a significant height above the “bell,” which fell next to the bell. As the water fell, it mixed with air which, entrained with the water, was swept below the surface. Because of the angle of the falling water carried the entrained air through the water in the pool at an angled, by the time the air rose up through the column of water, it was underneath the “mouth” of the bell, and so joined the air already in the “bell,” causing the water level inside the bell to drop, and the air inside it to “equalize” at a higher pressure than outside. Thus, a self-renewing source of pressurized air was made available to do work at in the pneumatic tools which were used in the mines. It was a very impressive system, and many decades later the pressurized pipes could still be seen (though they were no longer pressurized, of course).
I’m not going to lie, I did not expect this to be much of a video considering how simple the overall system is. But seeing you tweak your engine to gain so much run time out of such low pressure, really is amazing!
Very much liked seeing the Penny Farthing bike in the background! My good friend James Spillane of “My -trixs Manufacturing“ out of Madison, CT, USA and I and his son used to repair and build these bikes along with Columbia Eagle bikes as well and would showcase them during parades and other special events. Keep up the good work Mr. Stanton!
@@jakegarrett8109 but imagine taking a car tire and spinning it with your hands, and now think a tractor wheel. It would be too much weight for the engine to spin
@@AnonymousGuyyyy that's not how it works at all, and have you not seen cars like El Caminos with monster truck tires? The only difference is because of the larger outside diameter (higher effective gear ratio), you change the final drive ratio usually by using differentials. A huge portion of the kids in my class had off-road trucks with very nearly monster truck tires, that's what we were doing in shop class was welding things to jack their trucks feet off the ground, roll cages etc. You don't need an engineering degree to understand this stuff (by the way I do have degrees in mechanical and aerospace engineering, but this is just very basic elementary physics). Also more appropriate direct comparison to the wheels would be filling the wheels with concrete (you can also use water but due to moving fluid dynamics it's not the perfect comparison. That's actually a common thing, I've even filled tractor tires with water (increasing traction for pulling large loads). Also tractor tires often have iron or concrete weight in the tire rim and you can still turn those by hand (again the acceleration you can spin it up is proportionate to it's inertia).
Yes I like this Tom & as I am nearly 70, I had a thought for you. Get your mind off internal combustion engines! You don't need a piston, all of that is surplus to requirement. Your power comes form the air pressure on the large rubber diaphragm. The connecting rod only needs to be the size of the rod passing though your blue "piston", which you do not need & the other end of the rod fits onto the crank. Have fun.
At that low speed, the sound of the pin hitting the ball is very close to the sound of injector ping on a diesel. Beautiful engine, masterful engineering, as always
Here as well as in older air engine videos the propeller is purposefully put on the engine to act as a flywheel. But yea an actual flywheel of decent weight would be great.
My thoughts exactly, it evidently had the power to keep going but the inertia of only the propeller wasn’t quite sufficient to keep it stable. I feel like both designs could probably operate at a lower pressure if a dedicated flywheel was added to carry that momentum into the next stroke
Wouldnt a flywheel drain more air? Wouldnt that mean that the water (gravity from an energy perspective) cant keep the pressure in equlibrium? I dont think you thought this through, but im no physicist. Part of the reason it could keep going for so long was because it was slow and there was a 0.5 second gap between bangs. It would keep the engine running smooth, i agree but it would last less than a minute, wich was his goal to be fair. Edit: Wow i cant england... *wich goes against his goal to keep the engine running for long.
@@domonkosludvig3314 A fly wheel in a rotating mechanism works a lot like a capacitor in an electric power circuit. It takes away some energy from the peaks, and fills in the troughs. This means that the engine doesn't waste as much energy accelerating and decelerating, meaning that with each power stroke it hasn't lost as much speed and can get on with the stroke under better conditions. If you don't want it to run faster, you can reduce how much air is being allowed to flow, further reducing the consumption. Sure, a fly wheel costumes a little bit of energy, especially if it's not aerodynamic. But the gains far outweigh the cost.
As an electrical engineer, the first thing that came to my mind when you were laying out the tube was resistance. Kind of an interesting way to visualize "voltage" drop over a length of small gauge "wire" Awesome job with the engine. The diaphragm really transformed it!
The correct comparison would be drag in the tubing restricting water flow rate being the electrical equivalent of resistance limiting current in a wire. The pressure created by the height difference between the tank in the loft and engine downstairs is the equivalent of voltage (i.e. 'potential difference') across the wire, and won't change regardless of the diameter of the pipe / gauge of the wire.
@@richardjones38 You're currect about the first part, I was refering to the voltage drop that results from the resistance limiting current. Pressure (voltage) absolutely does change as current increases whenever you have a restriction. This is shown beautifully in the video as the pressure dropping as the flow increases.
Looking back through your videos, I realized you’re the only TH-camr I watch that I’ve watched every single one of your videos as they’ve been released. I think that’s due to your incredible creativity and making things I’ve never seen or thought of. Amazing stuff.
There’s another way to get air pressure out of water-by passing turbulent and aerated water flow, such as a stream or a garden hose, through a drop to pressurize it just a bit, you can allow the pressurized air fraction to rise up through a tube into a bottle, where it will gather into compressed air. The water will then rise back up to the level of the stream. This device is called a “trompe.” It would be really cool to make one (Practical Engineering built a demonstration out of PVC pipe you could look to as an example) and run the air engine off of the pressure output!
I can see more opportunities to increase the efficiencies. A couple of guides extending into the chamber and corresponding tabs on the piston. Should introduce more stability at low cost of friction. A little lubricant would also help. You could tinker away for a long time just experimenting with what improves performance. Maybe "borrow" a regulator from a compressor to stabilize the minimum pressure. One learns so much from iterative development. Thanks for the video!
This is absolutely amazing! I never thought of using water as a way to constantly keep pressure onto something. I did think of how water pressure could be used to create some sort of air battery, but not to keep a constant pressure. Even though not everything that is built for the sake of curiosity needs to be functional, I am curious if there are applications for this kind of technology. I could see this being useful in some way in areas with mountains due to the natural height differences. Maybe tall buildings could do something with this from rain water?
You might be interested in trompes. They aren't used too much today as far as I know, but they used to power mines, and use flowing water and a height difference to produce pressure.
If you want water for keeping pressure constant...also you must think about refilling the airbottle again after using all the air inside it. Maybe a system to empty that bottle down with a float...cutting of the water supply short, emptying the bottle down with other good use of that water and restarting the cycle....a system with 2 air bottles could make continues running possible with switching between those using a float. if there is enough water at the top (mountain)
@@bermchasin you could have a pressure(water) release valve at a certain height in the acrylic container. there are many possibilities here for what kind, perhaps the easiest would be a swing valve(attached to wall) with a floater fastened so that when the water reaches a certain elevation it also lifts the swing valve up letting the water escape. the height of the floater has to be a certain distance away from the swing valve so as to not let any air escape. another design would be a vertical ball valve attached to the side of the tank with a floater valve attached through to the tank with aluminium/steel wire and a floater on top. grabbity(air pressure) would hold the valve(ball) down until the water level would lift it with water. when the water level would go back down the valve would do too. maybe this is a more solid design.
Brilliant! And you could also use an old hot water tank as a reservoir, maybe even using collected rain water pressure, from a rooftop reservoir, via a regulator, to fill it, before using the water for other purposes such as cooking, washing, flushing the loo and watering the garden. If you were careful to use all of the water for other purposes, you could even use mains water. Finally, make a wind- or solar-powered pump to take water to an upper reservoir. Thanks Tom. 🙂👍
Tom, that was brilliant. You got me thinking about the possibility of gathering water in the roof from rain, as well as perhaps gathering moisture on the roof of a house by using tile surfaces (hopefully solar tiles) that nucleate water overnight, so droplets run down into 'catcher' to store water for electrical generation. Obviously rain is appealing in wet climates, but 'nucleating water' overnight, would appeal in moist temperate climates since its regular. I was thinking to catch air in the walls of the house for an added heat exchanger in the roof for more energy capture. Be a good man and make it all work for me. You're clearly the man to arrive at an integrated real life solution, for a house, and possibly a campervan. I'll happily collect the royalties for you. I'm strictly an ideas man. But I can count.
This is fascinating. I wonder how feasible it would be to link an array of closed cylinders up to a rain butt. When it rains, pressure would increase and you could take a cylinder to power something whenever you needed. A sort of 100% green and renewable battery. I imagine you'd need a few for it to be economical, but may work in very rainy countries. Interesting and great work as always!
Only problem with that idea is the rain collection container must be up very high to generate the pressure - and yet the roof space that would give you that extra pressure is above the drop of the water off the roof - in a taller building with many floors a tank up just under the gutter would work pretty well though. edit. Also should add it won't ever be a huge battery in capacity, its still a relatively small mass and short drop - however if you also say plumb that same tank to flush your toilet you will end up saving way more energy by using less drinking water for tasks that don't need such pure water.
That could actually be a cool idea for powering skyscrapers. Using the potential energy of rain water in the gutter to add some electricity to large buildings.
@@Ry_TSG problem is, the potential energy is minimal - not only do the roofs of skyscrapers don't catch that much water, but also the hight introduces negligible amouts of energy compared to the effort needed to build create and maintain a reliable system - but I like the idea as well :))
@@TecSanento The channel "Quint BUILDS" built a rooftop energy storage system. 55-gallon drum, set on the roof of his house, feeding a turbine at ground level. And it worked. But he calculated that the total energy storage as the equivalent of 1 AA battery.
Your channel is endlessly creative and this video is no exception, I really enjoyed this! That air-powered engine design was already really cool in your previous videos about it, but seeing it run on such low pressure is really impressive!
This made me pick out and have a look at my Air Hogs Accelerator air powered plane! I got it for my 7th birthday or so, so about 10 years ago, and haven't flown it for a few years. I remember it flying like crazy!
you could try powering it again with a pressurized bottle. i guess you tank had about 5-7 litters of air in it. if you pressutize a 2 litter bottle to like 7 bar (should be fine) you have around 14 liters of air. to stop the engine from spinning to fast you could add a pressure regulator and set it to around 0.4 bar. this should result in a mush longer runtime.
@@rickoshea8138 yea but those had the problem that they only run for a short time. With a pressure regulator and the low pressure of the engine it could run much longer
@@tjorvegro9651 Air pressure x volume dictates engine power. Power over time is the value. Simply making it turn for longer is nice to look at, but it needs to power something to be truly impressive.
@2:57 most materials cut well if you use the right rpm, feed rate, depth and step of cut and the right type of cutter/endmill. (all determined by pretty simple calculations). when i was a machinist i liked using 2 flute endmills on plastics and even aluminum endmills instead of highspeed steel or carbide. love your videos, great content.
Great job, you just keep making those engines better and better, amazing. I think it would be very interesting to see you use wider tubes. Also you could route the pressurized air back up and add that pressure to a secont water colum. Doubling your pressure. Having a high speed, high power version of this water enginge would be cool.
very intuitive demonstration of fluid dynamics, you really excel when it comes to explaining things, and also that is just fabulous how efficient this engine has evolved to be, it's come such a long way since the first iteration and your work is really something to marvel at
This was very interesting Tom, I would be excited to see how that new engine performs at higher pressures, such as your previous tests. additionally, how much pressure you could create with the top water tank at an even higher altitude. Also the effects of a larger diameter water tube on runtime and time to come back to operating pressure at the lower tank.
In the past, we used methylene chloride as a solvent for acrylic sheet. It does two things. First, you apply the methylene chloride between the two acrylic surfaces that you want to bond. After the application of the solvent, apply pressure until the solvent dries and the surfaces are permanently bonded. The second use of methylene chloride is that you can make a heavy slurry that can be used to create fillets between mating surfaces. This will give you additional strength at the mating surfaces. The downside of methylene chloride is it's considered carcinogenic. But with all chemical solvents care and the proper ppe are necessary.
Fun fact, theoretically speaking, putting mentos in coke and then quickly closing the cap should only be able to build the pressure up to the same level as if you had not put any mentos in and instead just let it naturally rebuild internal pressure over time. This is because the mentos is not actually reacting with the coke, it is simply providing high surface area for nucleation of the dissolved gas into bubbles. Without any chemical reaction, a closed bottle of coke (or any carbonated drink) can onlt change it's pressure as a result of temperature change.
EDIT: This comment is incorrect. Oops. A gas evaporating out of a liquid takes time though, and is limited by the pressure of the system. Providing nucleation sites doesn't add energy to the system, but it does reduce the energy needed for the CO2 to evaporate, which increases the pressure necessary to halt the evaporation, which in turn gives a much higher equilibrium pressure. Mentos don't chemically react with cola, but they do act as a catalyst, which changes the system. In that way, mentos cause a higher pressure from cola than just cola alone.
@@MrTridac -- Hmm, on second thought I think you're right. A catalyst would increase the speed of the equilibrium reaction in one direction, but it won't change the vapour pressure, so there would only be a tiny increase in equilibrium pressure if any.
Amazing. I love your videos, thank you. Initial thoughts: how about add a variable length needle that pushes on the ball at varying lengths depending on inlet pressure? So for example if the engine experiences a high amount of air pressure coming in ("lots of fuel available") then the pressure pushes a kind of lever that makes the needle Long, but if there is low air pressure ("low fuel environment") the engine "detects" this and the pressure only pushes the lever a small amount and the needle pushing the valve remains short, and the engine is able to operate at low pressure or high pressure. "Variable Pressure Engine Design" seems to be a logical direction you're headed.
In practical applications like propelling an airplane it is much more useful if you shorten the needle at high pressure and lengthen it at low pressure to regulate the rpm and power output, that can be done by replacing the needle with a spring. At low pressure the spring can easily push the ball without compressing and at high pressure the ball gets pushed down by the pressure causing the spring to compress while pushing the ball and therefore it gets shorter... A shorter needle at low pressure only makes sense if you just want to keep it spinning without drawing any power from the engine...
It's actually a Tom powered engine because you brought the water upstairs lol Or maybe a food powered engine because the food you ate that day gave you the energy to get up the stairs?
Even if you had a larger pipe to a smaller fitting on the lower tank would aid in reducing fictional losses. A major improvement in the rate to pressurize the tank would be to straighten the run of pipe as best you can, again to reduce frictional losses. flexible pipe is a good solution as you can avoid the 90degree bends that impact flow. Great job on it. Would be interesting to see if you could convert it to a water powered engine.
I’m not sure water power would work. The engine seems to rely on having the “fuel” expand in the cylinder, and water is incompressible. If would be cool if he tried it with other gasses, though.
@@Ry_TSG that's true! Potentially altering the pin length would be required to keep the valve open for longer, this would also require a much larger flow of the water, but could also greatly increase the torque.
I'd love a series on using an air powered engine with a pressure vessel that contains dry ice and liquid. It would be interesting to start with small amounts and play with ratios and volumes for the best run time.
Great video! Also, what if you use this engine in reverse, as a compressor, by powering it with electric motor? Would it work? What pressure can it get to? I think this is very intresting.
That wouldn't work, considering how the engine is designed. All the air would be pushed and pulled out of the exhaust, with only a very small amount being moved back and forth through the inlet. His previous design with a cam would probably work better for that, but considering the large amounts of air leaking around the sides of the piston, it probably wouldn't get past maybe 0.1 bar
Very cool stuff! Increasing the density of your fluid would let you reach higher pressures in the tank. Maybe you could use a saturated salt solution to increase the pressure (by about 1.2 times). OR you could go crazy and use mercury or something :)
While this seems unimpressive at first, if one thinks about the implications, it's super cool. If someone scaled this up a bit, then, just with rain water and a collection tank, or a small pump or human legs to carry it up every once in a while, you can have a fan that runs on zero fuel or electricity, just gravity and low pressures. That can help with air circulation and help a tiny bit with cooling during the summer (or at least the illusion of feeling cooler). This is really awesome and creative.
Very cool. I'd enjoy seeing some more refinements to the engine to reduce losses (more polishing of the piston and bore? More efficient diaphragm materials? Maybe route the exhaust air to act on the rear of the piston for a combined double-expansion double-acting action? (using the pressure left in the exhaust to help power the return stroke so less prop momentum is lost to that) and optimize the geometry. It's really entertaining to see you develop and test refinements. A small air pump connected to the air tank outlet would let you push the water back up to the storage tank and save some trips up the stairs carrying water.
No, the pressure isn't high enough. Steam engines didn't get double expansion until they got to several atm. The extra friction takes more power than it harvests at such low pressures.
Multiple expasion engines only used to prevent energy lost while steam expanding and temeprature drops. Or when small intake valve cutout is hard to implement. But air engine with piston-operated intake valve with automatical outake is not the case.
Another very cool project. I could see this being combined with a flywheel / rain collector for a small generator. You could use the motor you made for the e-bike, just re-wind the coils with more turns. Also, I'm curious how your engine compares in efficiency to an air-hogs engine. Could they run on pressures that low?
He gets his energy from food, food grows from the sun, sun is nuclear fusion. This entire system of engine+Tom+biosphere+sun is a nuclear fusion engine!
Maybe there's a way to add a float to release the water into a garden or something so that the tank can start a fresh cycle. Then it's like gravity fed irrigation combined with a fan. Seems like a nice addition to a mini greenhouse
Hey Tom awesome video as always! Looking at the design of the engine it seems it would be easy to make a radial version which would be cool if nothing else.
I think a bigger tube, even with the small inlet, would still help. Flow rate is a function of diameter and pressure. At the top, you don't have high pressure, so your diameter should be sufficient to have a high flow rate. But at the bottom, the pressure is higher, so a size reduction and a smaller inlet at the bottom should suffice. A bigger inlet will ofc still be better too. As that will cause less pressure differential at the bottom (thus less pressure loss before the flow rate can give you an equilibrium). But changing the top and tube alone will help.
You should try to "supercharge" the design by adding a pump to either increase the pressure in the hose, Or add an secondary tank instead of the open upper reservoir, and in order to get it started have some kind of one way valve, and pump extra pressure into the upper reservoir.
Just a hint for cnc milling plastics is to fit an air nozzle to the mill head aimed at the tool to keep it cool. Stops all that softening and spring back that happens when the tool and the work get too hot.
In this design of engine, you could further reduce friction by an order of magnitude and lighten your rotating assembly by getting rid of the plastic piston and simply using a small piece of brass rod in a sleeve with your dome and pin affixed to it.
It would be cool to see this scaled up. I know it’s not really efficient or practical for much, but imagine using an engine like this made out of steel/aluminum parts with a large 100+ gal water tank at 50 feet plus, with a steel pressure chamber at the base.
Nice work! I wonder if lubing the engine would reduce friction and increase compression. Watching the video, I realized that the engine might work from pressured water too.
I always wondered about doing this with a ram pump. If you have property with a river or Creek with differences in elevation you could practically have free endless water and air pressure.
A great idea and good motivation to further improve your air piston design. With all these improvements ya aughta hook one up to a plane again and see how well it does
You could try putting a one way valve at the water inlet and than pressurize the tank with a bike pump. That way it runs longer and the water can push in more pressure as it gets lower.
Definitely recommend getting a resin printer for precision jobs. All you need is a good mix of tough/flexible resing(~20% or os) with normal resin and you can print really strong parts, or even springs, that are very accurate. You could combine the two printing technologies. FDM for the bulk and structure, resin for precision parts.
I really hope we get to see this air engine in common ICE engine configurations-should theoretically be a walk in the park considering there's no valve train. I'd love to see efficiency compared as well
OK, sorry if it has been suggested: As it is a closed system and once the water is all "down stairs" you have to empty the cylinder and put it back upstairs. Yes, this could be seen as "cheating", but why not add a third hole in the top of the cylinder and connect an air pump. Then, when it is full of water you: a) close the output to the engine b) turn on the compressor and pump the water back upstairs. Similar to how hydroelectric power stations work. Water being used in the daytime and pumped back up at night. Just a thought.
I am not sure what the appliance for this would be, but I like it! You could get higher pressure by using a second cylinder instead of the upstairs bucket and then weigh it down.
You could have simply used the municipal water supply from your kitchen tap connected directly to your pressure tank. The supply is from tank which is much higher than that of your first floor.
In case you are not aware, a failing pressure vessel filled with gas is significantly more dangerous than one filled with water. That's why most tanks are hydrostatic tested. If a tank ruptures, the gas will continue to apply force while expanding until it equalizes with atmospheric pressure. This can produce significant acceleration of the tank fragments making them white dangerous. Meanwhile, since a fluid is effectively incompressible, when the container ruptures, there's almost no expansion, and very little force transferred to the fragments.
It's insane how you can make that engine run at such low pressures
What a madlad
Sup
It's insane how you can make TOMATOES run at such low pressure.
give me a 3d printer or im sending 15 tomatoes to your PO box (they will rot)
Yes. Also he didnt crush tomatoes
My suggestion would be lubrication of the moving parts. Using something like dry Teflon lubricant, graphite, or even a pencil I imagine can make a difference when the air pressure drops even more. Also, real internal combustion engines use a weighted flywheel to smooth themselves out and keep their rotational inertia going between ignition strokes, since in a normal single-cylinder four-stroke engine, there's quite a lot of time between ignition because the piston has to go up and down three more times until the next power stroke. When the air engine slows down and starts oscillating, it's likely because it loses inertia and needs something to keep it spinning in one direction, not to mention smoothing it out. Something heavier than a carbon fiber propeller like an aluminum disc.
That would also make use of the extra energy the engine has in the beginning when the pressure is higher than the equilibrium point, allowing it to speed up!
Yeah. Quick squirt of silicon maybe
@@twobob No, silicon grease has too much drag
Teflon is a carcinogen and should be banned
Here's an idea. Glycerin. Water soluble, thin, and lubricating.
Love the engine designs! The modification processes and changes over time have been really interesting to watch. Thanks for the great content!
Awesome build! It’s really cool to see the ways you were still able to squeeze higher efficiencies from the motor even after all of the iterative work you’d done to improve it in the previous video!
the solution to your issue is to add more cylinders :3 being able to apply at different stroke phases will enhance efficiency as the blade wont be accelerating and slowing down as often (which is how the change in direction occurs), and the resulting increase in total diaphragm area will allow it to run better at lower pressures. Have you considered adding some intertial mass (flywheel) to the system to also help balance out the power application of the motor to stop the accel/decell issues it has?
those are good suggestions
Crank would be really weird
I don't think 2 more cylinders will work because it will draw 2 times more air and the water won't have time to build up pressure for 2 more cylinders
@@gurraflex6478 it would be a tradeoff - more power for less runtime.
Wonderful!
You could add a floater into the tank to that automatically blocks the outlet as soon as the water reaches the top. That way you don't have to worry about flooding the engine.
Came to the comments knowing someone else thought of this too!
Great job, Tom! Always enjoy watching you build and enjoy whatever it is you are building!
Hehe, "flooding," but it's water.
I had an idea for a practical use of this: toilet flush powered air circulation. The tank would need to be made specifically for this task, but after flushing, while it fills up it would power a fan.
No need to block the output, he needs to add an air tank to the output, connect them with a one-way valve, and make a swimmer to dump the water out. The valve+tank setup will keep the air pressure going while the tank empties and refills.
Fun fact, having an open system like that with a tank on the loft, is actually how you pressurized the central heating system in houses back in the day 😄
Here in Denmark they used to measure the water pressure in the system in mVs (meter vand søjle) meaning “meter water height” I suppose. Basically one meter is equal to .1 bar of pressure :)
pumps are commonly spec'd in meters/feets of "head"
What do you mean, back in the day? I do still own one fifth of a house that has a central heating system like that.
And yes, I learned the hard way that was how it worked. Because yes, when the house had been connected to the municipal water system, there was a valve through which you could repressurize the central heating system, and no, the open tank up in the second floor wasn't removed... And no, I didn't overfill the system directly, I did follow the pressure gage. But the heater got the water in the system too hot because of some wrong settings. I did get all the warm water cleared before it had a chance to get soaked in anywhere. Luckily. But that was still quite dramatic.
I still don't drink warm water out of the tap, even though it's all combi-boilers nowadays.
Today they will burn coal, in order to spin a steam engine at high pressure, then run that energy in form of electricity over miles upon miles of copper power lines into your house to charge you for it. Not at all wasteful, not ever heard of energy transfer loss of (80%+!). When instead you could just burn that coal right at your home from wood on your property to minimize cost and waste (SHhhSHSHSHhhhhhh) dont tell anyone you'll get shad0wb4nn3d! Well, or in this case, instead of burning coal, just carry some tanks of water upstairs every day to run a small dynamo to charge the basic of electronics. Or collect some rain water from the roof and channel it into the system.
You can do the same thing with running water for infinite compressed air using something called a trompe. Mines and other industries that use a lot of compressed air have used this technique for creating compressed air for nearly as long as the need for compressed air has existed. All you need is plenty of water and a change in elevation. Also worth noting is that you get more air pressure from a trompe then you do from a static column of water thanks to the inertia of the water as it falls similar to how a ramp pump provides more pressure out than the input pressure.
I was about to suggest a trompe as well--that way, there's no need to cut the water supply to avoid drowning the engine, since the trompe draws in outside air as long as the water keeps flowing.
yes, but it requires a continuous flow of water..a LOT of water. Works great if you have a stream or something doing nothing anyway, a lot less great if you have to move all that water back to the top when your done.
Tromped are soooo rad
I always think those are so cool. They are a great combination of a lot of important concepts. The first person to see one of those systems had to be totally amazed.
Mr Thessalonian channel has a hybrid Trump and hydraulic ram mix that gets 60 PSI from a unit built from a propane tank.
I don't know exactly what it is, but I could watch your air engines puffin away for HOURS without getting bored! This must be the most wholesome and entertaining piece of tech I ever saw coming out of a 3d printer and I am kinda sad, that I lack the technical knowhow and equipment to do stuff like that. Thank god for people like you who can scratch that itch for me anyway :D
Why are watching and hearing engines spin so satisfying?
@@KainniaK'cause hes a Kerbal
th-cam.com/video/dQw4w9WgXcQ/w-d-xo.htmlsi=vxWwEQ-ODrr9JzUW
My dad told me a few years ago that my grandpa actually used air engines to run a pump when he was working which I find fascinating. I had first heard of these when I was going to school for drafting, I had built a design for one and played around with a 3d print as well. At that time I didn't think that it was anything more than just a representation of what could be done if you play around with physics but since then I have been absolutely obsessed with these
alot of wineries still use air-powered pumps to move wine
That is honestly the cleanest looking DIY I've ever seen. Good job, Tom!
Not to take credit away from Tom, because it does looks very clean and it is was for sure an interesting video! But you should look up "DIY Perks" for some amazing projects
It's very clean because of all the water
its not diy anymore its ingenearing.
and its much better than 5 min craft shit XD
Please be careful with acrylic pressure tanks. They tend to fail catastrophically. Not a problem at those low pressures but once you go above that, add a layer of translucent tape around it that keeps the acrylic parts from flying everywhere in case of failure.
Mans is smart enough to not over look something so trivial
@@XXLNative Gotta get that knowledge somewhere!
Also, that acrylic cylinder design is a terrible pressure vessel shape...
@@namibjDerEchte To be fair, he talked about that and it was for simplicities sake.
Pressure vessels are typically designed to bend and leak, rather than break at the strength of the material. This one is probably done wrong, so yeah, failure mode is an important consideration.
You don't need a larger ports to reduce you're losses from the water flowing through the tube. If you put an adapter on the inlet to the pressure chamber and the outlet of the upstairs tank that adapts to a larger diameter tube, you will increase your flow rate even without changing threaded port size.
This is because most of your losses are not coming from the simple restriction of the flow cross section, but rather from the friction against the wall of the tube. In fact, in hydraulic engineering (ie engineering of any fluid conveyance system) the losses due to flow restricting components are referred to as "minor" head loss while those due to wall friction are "major" head loss because of how much higher they usually are.
If you look at the equation for major head loss you'll see it is the Darcy Friction Factor (usually given the symbol f with subscript D) multiplied by the tube or pipe length, divided by the hydraulic diameter (just the inner diameter in the case of circular cross sections). This means that you can reduce your major head loss significantly by simply adapting to a larger tube diameter, and then just accept that the minor head losses from the comparatively undersized ports at either end.
Now use your engine to compress air into the tank and it will run forever.
Not
The flow rate for given pressure gradient during laminar flow actually scales as the *4th power* of the diameter.
So increase the diameter by a factor 2, gain 16x the flow (or increase by only 20% to double it, roughly).
@@landsgevaer last i checked the formula for major headloss was proportional to D^-1 not D^-4. could you elaborate on what model that predicts a D^-4 relationship?
@@maxk4324 Laminar flow in a tube. Speed goes like diameter squared since it has a parabolic velocity profile, multiplied by cross sectional area that also goes like diameter squared.
en.m.wikipedia.org/wiki/Hagen%E2%80%93Poiseuille_equation
Initially I thought that turbilent flow might scale with a lower power, but linear with diameter seems weird since then the velocity in the center of the tube would need to decrease with diameter, given that flow scales with area.
Not sure what you mean with this major head thingy, so maybe you can give your reference too...? 😉
TIP, when you pour water from a container. Spout uppermost, better flow and more control. Great video as always. J
Also to the side is a good compromise, when you need to align the spout with target container more precisely.
This is like a fluid over air cylinder in automation for industry. They do work really good at lower pressures. I hardly had any problems with them in my previous encounters as a maintenance employee at a large automotive plant.
The flow rate is limited much more by friction losses in the long tube than by the size of the fittings. If you printed some adapters and replaced the tube with one that has a larger diameter, the pressure probably would stay at a value much closer to 0.6 bar.
I was looking for this comment.
Also straightening the path the tubing takes will reduce the friction losses.
Yeah I thought so too. I would definitely like to see an attempt with a bigger tube!
So, interestingly, you have definite starting and ending quantities of air, and you can easily (😟) count the number of rotations. This will tell you exactly how much air is spent on each rotation which would be very interesting to compare to the volume of your cylinder. It would tell you how much air leaks on every stroke. It seems like that number would be pretty small.
Except he doesn't have a "cylinder", it's the weird flying saucer shaped area above the diaphragm and that doesn't get filled with air at the inlet pressure since the valve only opens for a short time.
I wonder if you could get more air volume by putting a T fitting and a schrader valve below the pressure gauge, then pump the water back up to the reservoir with a bike pump by pumping air into the tank?
@@mjolnirswrath23 Energy is conferred to the motor by removing air from the system (allowing more water to run down from above, transferring the water's gravitational potential energy into air pressure, and from there into kinetic energy in the motor); in a closed loop the air trying to go back into the tank would be fighting water pressure, which would stop the system (or, alternate explanation, if the air is allowed back into the tank it would prevent water from flowing down, stopping more energy from making it to the motor, the system would be at equilibrium and no movement would happen).
Similarly, collecting the water from hydrogen combustion is all well and good, but energy still needs to be re-introduced into the water to separate it back into oxygen and hydrogen before it's fuel again. Unfortunately there's no such thing as infinite energy, it has to come from somewhere.
@@mjolnirswrath23 I cant understand a fucking thing you're saying.
@@FoxSock man, he must've deleted his comment. I don't suppose you remember what he said?
It's amazing how well the engine self-regulates, slower RPMs meaning it consumes less air per second and lets the pressure build back up. Would a heavier flywheel help it avoid stalling at very low RPM, or just keep the RPM high until it starves itself of air?
A flywheel only helps at smoothing the motion between power strokes, it is not needed to reach high speeds, hence why he didnt use it previously.
It would have definitely been useful here to maintain a smoother rotation tho
Not necessarily a heavy flywheel but someting with high moment of inertia. The large diameter propeller blades already serve this purpose.
I think a heavy flywheel would be helpful. Think about those old hit-and-miss engines. They had massive flywheels and they could operate at low RPMs, like 250 RPMs. There are accelerations and decelerations of the piston, rod, and crankshaft in every rotation. A heavy flywheel would stabilize the accelerations and deccelerations. Which would increase the efficiency. I don't think that the propeller has enough weight. I would try something like a wheel from a push lawnmower or an aluminum pulley for a belt drive about 6 inches in diameter.
Thought I might mention that as I understand it, most of the water pressure loss is in the plastic pipe, and a bit in the fittings, replacing the pipe alone should significantly increase the water flow rate. Besides that loved your enthusiasm to discover something new. Wonderful stuff!
You need to design an Air tank that maintains pressure at a constant, without the weight of water. Some sort of self collapsing tank that inflates with the air pressure and slowly reduces the inner space with an equal opposing force. Maintaining a steady slow collapse and low weight, would be the key.
Here is an idea,instead of having 2 pressure chambers,make it 3,one above the other to provide water,2nd one to provide pressure,and you can make a hole up on the half of the cylinder for water drainage system.So chamber number 3 will collect water,it would be intresting to put it on some sort of moving platform where chambers 1 and 3 will switch places constantly as one drains and other provides water as needed.But you will have to constantly rotate the chamber number 2 because of the holes for drainage/providing.This all can be solved with 2 electromotors one for moving the platform of chambers up and down,and other to rotate/flip 180 degress the middle chamber.I think with this system in place it could seriously provide some close to similar perpetual motion(Mind that you need electricity for that 2 electro motors).Just a thought..
This project reminds me of a TH-cam video I once watched, which discussed a unique power source for pneumatic tools that were needed for mining in a remote town somewhere in Canada. It used an cylindrical bell-like structure (made of iron or steel, if I remember correctly), which had a fitting at the top, through which pressurized air could be fed into pipes and hoses that attached to the various tools that were used (drills, power-hammers, conveyer belts, etc). The “mouth” of the bell was lowered into a deep pool in a nearby river, which trapped the air in the bell below the surface of the water, so that the air in the bell was compressed by the surrounding water. Then, as I understand it, they brought water, via an aqueduct, to a fluke that ended at a significant height above the “bell,” which fell next to the bell. As the water fell, it mixed with air which, entrained with the water, was swept below the surface. Because of the angle of the falling water carried the entrained air through the water in the pool at an angled, by the time the air rose up through the column of water, it was underneath the “mouth” of the bell, and so joined the air already in the “bell,” causing the water level inside the bell to drop, and the air inside it to “equalize” at a higher pressure than outside. Thus, a self-renewing source of pressurized air was made available to do work at in the pneumatic tools which were used in the mines. It was a very impressive system, and many decades later the pressurized pipes could still be seen (though they were no longer pressurized, of course).
Sounds quite eco friendly. Like hydropower without electricity
I believe you are talking about a trompe
en.wikipedia.org/wiki/Trompe
trump pump 🤔
Ragged Chute!
th-cam.com/video/uvf0lD5xzH0/w-d-xo.html&vl=en
Lake Nyos has something similar, I believe. Except these were used to remove harmful gas from the bottom of the water column.
Tom Stanton + little air engines is one of my favourite pairings on youtube. I love each installment with it's innovations. beautiful
I’m not going to lie, I did not expect this to be much of a video considering how simple the overall system is.
But seeing you tweak your engine to gain so much run time out of such low pressure, really is amazing!
The last person who made an engine run out of water mysteriously died
No they didn’t.
@@Mostlyharmless1985 they did
@@Pcbuilder28 no they didn’t.
@@Mostlyharmless1985they were poisoned
@@Jeditz172Nuh uhhh
Very much liked seeing the Penny Farthing bike in the background! My good friend James Spillane of “My -trixs Manufacturing“ out of Madison, CT, USA and I and his son used to repair and build these bikes along with Columbia Eagle bikes as well and would showcase them during parades and other special events. Keep up the good work Mr. Stanton!
i'd love to see a low pressure twin cylinder. might work a little smoother even with the added complexity and friction
Or just add a flywheel
Then a needle valve for air flow balance.
@@kricketflyd111 just synchronize timing like a steam engine, simple ports like a 2 stroke even
Efficiency! I love seeing the engine improvements, very satisfying to see designs getting refined.
Nice build! You could also add a flywheel to help maintain stability and rotation direction. Might be helpful.
But it would probably add too much weight for 0,4 bar of air
@@AnonymousGuyyyy It only adds inertia, and he's hand starting it.
@@jakegarrett8109 but imagine taking a car tire and spinning it with your hands, and now think a tractor wheel. It would be too much weight for the engine to spin
@@AnonymousGuyyyy that's not how it works at all, and have you not seen cars like El Caminos with monster truck tires? The only difference is because of the larger outside diameter (higher effective gear ratio), you change the final drive ratio usually by using differentials.
A huge portion of the kids in my class had off-road trucks with very nearly monster truck tires, that's what we were doing in shop class was welding things to jack their trucks feet off the ground, roll cages etc.
You don't need an engineering degree to understand this stuff (by the way I do have degrees in mechanical and aerospace engineering, but this is just very basic elementary physics). Also more appropriate direct comparison to the wheels would be filling the wheels with concrete (you can also use water but due to moving fluid dynamics it's not the perfect comparison. That's actually a common thing, I've even filled tractor tires with water (increasing traction for pulling large loads). Also tractor tires often have iron or concrete weight in the tire rim and you can still turn those by hand (again the acceleration you can spin it up is proportionate to it's inertia).
@@jakegarrett8109 i dunno, i’m a dumbass. You’re probably right
Yes I like this Tom & as I am nearly 70, I had a thought for you. Get your mind off internal combustion engines! You don't need a piston, all
of that is surplus to requirement. Your power comes form the air pressure on the large rubber diaphragm. The connecting rod only needs
to be the size of the rod passing though your blue "piston", which you do not need & the other end of the rod fits onto the crank.
Have fun.
At that low speed, the sound of the pin hitting the ball is very close to the sound of injector ping on a diesel. Beautiful engine, masterful engineering, as always
Very impressive. I'd be interested to see you try adding a flywheel to that. I suspect that it will be a lot more stable at low speeds.
Here as well as in older air engine videos the propeller is purposefully put on the engine to act as a flywheel.
But yea an actual flywheel of decent weight would be great.
My thoughts exactly, it evidently had the power to keep going but the inertia of only the propeller wasn’t quite sufficient to keep it stable. I feel like both designs could probably operate at a lower pressure if a dedicated flywheel was added to carry that momentum into the next stroke
I imagine the propeller is very light since its made from CF
Wouldnt a flywheel drain more air? Wouldnt that mean that the water (gravity from an energy perspective) cant keep the pressure in equlibrium? I dont think you thought this through, but im no physicist.
Part of the reason it could keep going for so long was because it was slow and there was a 0.5 second gap between bangs.
It would keep the engine running smooth, i agree but it would last less than a minute, wich was his goal to be fair.
Edit: Wow i cant england... *wich goes against his goal to keep the engine running for long.
@@domonkosludvig3314 A fly wheel in a rotating mechanism works a lot like a capacitor in an electric power circuit. It takes away some energy from the peaks, and fills in the troughs. This means that the engine doesn't waste as much energy accelerating and decelerating, meaning that with each power stroke it hasn't lost as much speed and can get on with the stroke under better conditions. If you don't want it to run faster, you can reduce how much air is being allowed to flow, further reducing the consumption.
Sure, a fly wheel costumes a little bit of energy, especially if it's not aerodynamic. But the gains far outweigh the cost.
As an electrical engineer, the first thing that came to my mind when you were laying out the tube was resistance. Kind of an interesting way to visualize "voltage" drop over a length of small gauge "wire"
Awesome job with the engine. The diaphragm really transformed it!
The correct comparison would be drag in the tubing restricting water flow rate being the electrical equivalent of resistance limiting current in a wire.
The pressure created by the height difference between the tank in the loft and engine downstairs is the equivalent of voltage (i.e. 'potential difference') across the wire, and won't change regardless of the diameter of the pipe / gauge of the wire.
@@richardjones38 You're currect about the first part, I was refering to the voltage drop that results from the resistance limiting current.
Pressure (voltage) absolutely does change as current increases whenever you have a restriction. This is shown beautifully in the video as the pressure dropping as the flow increases.
Looking back through your videos, I realized you’re the only TH-camr I watch that I’ve watched every single one of your videos as they’ve been released. I think that’s due to your incredible creativity and making things I’ve never seen or thought of. Amazing stuff.
There’s another way to get air pressure out of water-by passing turbulent and aerated water flow, such as a stream or a garden hose, through a drop to pressurize it just a bit, you can allow the pressurized air fraction to rise up through a tube into a bottle, where it will gather into compressed air. The water will then rise back up to the level of the stream. This device is called a “trompe.” It would be really cool to make one (Practical Engineering built a demonstration out of PVC pipe you could look to as an example) and run the air engine off of the pressure output!
I can see more opportunities to increase the efficiencies. A couple of guides extending into the chamber and corresponding tabs on the piston. Should introduce more stability at low cost of friction. A little lubricant would also help. You could tinker away for a long time just experimenting with what improves performance. Maybe "borrow" a regulator from a compressor to stabilize the minimum pressure. One learns so much from iterative development. Thanks for the video!
Man your vids are so cool, “props” to you for being able to make so much content with the ideas of harnessing and converting types of energy.
Areola Dan
Honestly one of my favorite engineering TH-camrs.
and your face was really cool oooooooooooo nice
This is absolutely amazing! I never thought of using water as a way to constantly keep pressure onto something. I did think of how water pressure could be used to create some sort of air battery, but not to keep a constant pressure.
Even though not everything that is built for the sake of curiosity needs to be functional, I am curious if there are applications for this kind of technology. I could see this being useful in some way in areas with mountains due to the natural height differences. Maybe tall buildings could do something with this from rain water?
You might be interested in trompes. They aren't used too much today as far as I know, but they used to power mines, and use flowing water and a height difference to produce pressure.
If you want water for keeping pressure constant...also you must think about refilling the airbottle again after using all the air inside it. Maybe a system to empty that bottle down with a float...cutting of the water supply short, emptying the bottle down with other good use of that water and restarting the cycle....a system with 2 air bottles could make continues running possible with switching between those using a float. if there is enough water at the top (mountain)
Connect it to a tap instead and get that sweet constant 80psi (give or take 20psi).
56 here.
until it fills up.
@@bermchasin you could have a pressure(water) release valve at a certain height in the acrylic container. there are many possibilities here for what kind, perhaps the easiest would be a swing valve(attached to wall) with a floater fastened so that when the water reaches a certain elevation it also lifts the swing valve up letting the water escape. the height of the floater has to be a certain distance away from the swing valve so as to not let any air escape.
another design would be a vertical ball valve attached to the side of the tank with a floater valve attached through to the tank with aluminium/steel wire and a floater on top. grabbity(air pressure) would hold the valve(ball) down until the water level would lift it with water. when the water level would go back down the valve would do too. maybe this is a more solid design.
@@bermchasin have 3 reservoirs, switch between them and let gravity drain.
Brilliant! And you could also use an old hot water tank as a reservoir, maybe even using collected rain water pressure, from a rooftop reservoir, via a regulator, to fill it, before using the water for other purposes such as cooking, washing, flushing the loo and watering the garden. If you were careful to use all of the water for other purposes, you could even use mains water. Finally, make a wind- or solar-powered pump to take water to an upper reservoir. Thanks Tom. 🙂👍
Tom, that was brilliant. You got me thinking about the possibility of gathering water in the roof from rain, as well as perhaps gathering moisture on the roof of a house by using tile surfaces (hopefully solar tiles) that nucleate water overnight, so droplets run down into 'catcher' to store water for electrical generation. Obviously rain is appealing in wet climates, but 'nucleating water' overnight, would appeal in moist temperate climates since its regular. I was thinking to catch air in the walls of the house for an added heat exchanger in the roof for more energy capture. Be a good man and make it all work for me.
You're clearly the man to arrive at an integrated real life solution, for a house, and possibly a campervan. I'll happily collect the royalties for you. I'm strictly an ideas man. But I can count.
This is fascinating. I wonder how feasible it would be to link an array of closed cylinders up to a rain butt. When it rains, pressure would increase and you could take a cylinder to power something whenever you needed. A sort of 100% green and renewable battery. I imagine you'd need a few for it to be economical, but may work in very rainy countries. Interesting and great work as always!
Only problem with that idea is the rain collection container must be up very high to generate the pressure - and yet the roof space that would give you that extra pressure is above the drop of the water off the roof - in a taller building with many floors a tank up just under the gutter would work pretty well though.
edit. Also should add it won't ever be a huge battery in capacity, its still a relatively small mass and short drop - however if you also say plumb that same tank to flush your toilet you will end up saving way more energy by using less drinking water for tasks that don't need such pure water.
That could actually be a cool idea for powering skyscrapers. Using the potential energy of rain water in the gutter to add some electricity to large buildings.
@@Ry_TSG problem is, the potential energy is minimal - not only do the roofs of skyscrapers don't catch that much water, but also the hight introduces negligible amouts of energy compared to the effort needed to build create and maintain a reliable system - but I like the idea as well :))
@@TecSanento The channel "Quint BUILDS" built a rooftop energy storage system.
55-gallon drum, set on the roof of his house, feeding a turbine at ground level. And it worked.
But he calculated that the total energy storage as the equivalent of 1 AA battery.
@@rogerrabbit80 yeah i know this video, thats why i wrote my comment - all this effort for bascally nothing
Your videos are part of the reason why I did an 180 in carreer planning and study mechanical engineering now!
Cool
Your channel is endlessly creative and this video is no exception, I really enjoyed this!
That air-powered engine design was already really cool in your previous videos about it, but seeing it run on such low pressure is really impressive!
You should make two cylinders to your square piston design and and you should see if it can run off water
This made me pick out and have a look at my Air Hogs Accelerator air powered plane! I got it for my 7th birthday or so, so about 10 years ago, and haven't flown it for a few years. I remember it flying like crazy!
This actually blew my mind, especially when it sort of reached that self sustainability and kept the pressure stable. Great video!
I love watching your ideas being tested. When they work, it's a rush. This is why we create/build/test things!!!
you could try powering it again with a pressurized bottle. i guess you tank had about 5-7 litters of air in it. if you pressutize a 2 litter bottle to like 7 bar (should be fine) you have around 14 liters of air. to stop the engine from spinning to fast you could add a pressure regulator and set it to around 0.4 bar. this should result in a mush longer runtime.
Look at his other videos. Lots of bottles there.
@@rickoshea8138 yea but those had the problem that they only run for a short time. With a pressure regulator and the low pressure of the engine it could run much longer
@@tjorvegro9651 Air pressure x volume dictates engine power. Power over time is the value. Simply making it turn for longer is nice to look at, but it needs to power something to be truly impressive.
I’d love to see your new efficient engine run on this setup!
@2:57 most materials cut well if you use the right rpm, feed rate, depth and step of cut and the right type of cutter/endmill. (all determined by pretty simple calculations). when i was a machinist i liked using 2 flute endmills on plastics and even aluminum endmills instead of highspeed steel or carbide. love your videos, great content.
Great job, you just keep making those engines better and better, amazing. I think it would be very interesting to see you use wider tubes. Also you could route the pressurized air back up and add that pressure to a secont water colum. Doubling your pressure. Having a high speed, high power version of this water enginge would be cool.
very intuitive demonstration of fluid dynamics, you really excel when it comes to explaining things, and also that is just fabulous how efficient this engine has evolved to be, it's come such a long way since the first iteration and your work is really something to marvel at
This was very interesting Tom, I would be excited to see how that new engine performs at higher pressures, such as your previous tests. additionally, how much pressure you could create with the top water tank at an even higher altitude. Also the effects of a larger diameter water tube on runtime and time to come back to operating pressure at the lower tank.
In the past, we used methylene chloride as a solvent for acrylic sheet. It does two things. First, you apply the methylene chloride between the two acrylic surfaces that you want to bond. After the application of the solvent, apply pressure until the solvent dries and the surfaces are permanently bonded. The second use of methylene chloride is that you can make a heavy slurry that can be used to create fillets between mating surfaces. This will give you additional strength at the mating surfaces. The downside of methylene chloride is it's considered carcinogenic. But with all chemical solvents care and the proper ppe are necessary.
This is delightful. Well done. I’d love to see how this works with the more optimised air engine design you detailed in your most recent video!
Fun fact, theoretically speaking, putting mentos in coke and then quickly closing the cap should only be able to build the pressure up to the same level as if you had not put any mentos in and instead just let it naturally rebuild internal pressure over time. This is because the mentos is not actually reacting with the coke, it is simply providing high surface area for nucleation of the dissolved gas into bubbles. Without any chemical reaction, a closed bottle of coke (or any carbonated drink) can onlt change it's pressure as a result of temperature change.
EDIT: This comment is incorrect. Oops.
A gas evaporating out of a liquid takes time though, and is limited by the pressure of the system. Providing nucleation sites doesn't add energy to the system, but it does reduce the energy needed for the CO2 to evaporate, which increases the pressure necessary to halt the evaporation, which in turn gives a much higher equilibrium pressure.
Mentos don't chemically react with cola, but they do act as a catalyst, which changes the system. In that way, mentos cause a higher pressure from cola than just cola alone.
@@TlalocTemporal Since it's all CO2, wouldn't it redissolve into the water if the pressure is higher than the vapor pressure of CO2.
@@MrTridac -- Hmm, on second thought I think you're right. A catalyst would increase the speed of the equilibrium reaction in one direction, but it won't change the vapour pressure, so there would only be a tiny increase in equilibrium pressure if any.
Amazing. I love your videos, thank you.
Initial thoughts: how about add a variable length needle that pushes on the ball at varying lengths depending on inlet pressure? So for example if the engine experiences a high amount of air pressure coming in ("lots of fuel available") then the pressure pushes a kind of lever that makes the needle Long, but if there is low air pressure ("low fuel environment") the engine "detects" this and the pressure only pushes the lever a small amount and the needle pushing the valve remains short, and the engine is able to operate at low pressure or high pressure. "Variable Pressure Engine Design" seems to be a logical direction you're headed.
In practical applications like propelling an airplane it is much more useful if you shorten the needle at high pressure and lengthen it at low pressure to regulate the rpm and power output, that can be done by replacing the needle with a spring. At low pressure the spring can easily push the ball without compressing and at high pressure the ball gets pushed down by the pressure causing the spring to compress while pushing the ball and therefore it gets shorter...
A shorter needle at low pressure only makes sense if you just want to keep it spinning without drawing any power from the engine...
@@Henning_S. this comment section is so educated
Amazing new design!
You should definitely compare the efficiency of the new engine with some of the previous versions.
It's actually a Tom powered engine because you brought the water upstairs lol Or maybe a food powered engine because the food you ate that day gave you the energy to get up the stairs?
This man needs for credit for these videos!🧑💻
Even if you had a larger pipe to a smaller fitting on the lower tank would aid in reducing fictional losses. A major improvement in the rate to pressurize the tank would be to straighten the run of pipe as best you can, again to reduce frictional losses. flexible pipe is a good solution as you can avoid the 90degree bends that impact flow. Great job on it. Would be interesting to see if you could convert it to a water powered engine.
I’m not sure water power would work. The engine seems to rely on having the “fuel” expand in the cylinder, and water is incompressible. If would be cool if he tried it with other gasses, though.
@@Ry_TSG that's true! Potentially altering the pin length would be required to keep the valve open for longer, this would also require a much larger flow of the water, but could also greatly increase the torque.
I'd love a series on using an air powered engine with a pressure vessel that contains dry ice and liquid. It would be interesting to start with small amounts and play with ratios and volumes for the best run time.
A dry ice engine, that would be really interesting. I've never seen one.
Great video! Also, what if you use this engine in reverse, as a compressor, by powering it with electric motor? Would it work? What pressure can it get to? I think this is very intresting.
That wouldn't work, considering how the engine is designed. All the air would be pushed and pulled out of the exhaust, with only a very small amount being moved back and forth through the inlet. His previous design with a cam would probably work better for that, but considering the large amounts of air leaking around the sides of the piston, it probably wouldn't get past maybe 0.1 bar
The diaphragm design only works in one direction
Water engines would be so good for our atmosphere too! Mist getting released instead of co2 just imagine!
As a heads up for future reference super glue is actually amazing for bonding acrylic as super glue is cyanoacrylate and melts the pieces together.
Very cool stuff! Increasing the density of your fluid would let you reach higher pressures in the tank. Maybe you could use a saturated salt solution to increase the pressure (by about 1.2 times). OR you could go crazy and use mercury or something :)
Use barbecue sauce. That stuff could probably hold more pressure than the tank! Plus your "exhaust" might smell tasty. Lol
An engine that will randomly change direction seems like something that would keep life properly exciting, don't you think?
It would be very interesting if my car did that
@@KingJellyfishII "oh, the engine reversed, gotta change to reverse gears again"
Spicing things up ? :D
@@bluesillybeard "damn it not again"
That's how you reverse a Lanz Bulldog.
Your videos bring Christmas morning level excitement every time I see a notification. Thank you for all the quality content
This
While this seems unimpressive at first, if one thinks about the implications, it's super cool. If someone scaled this up a bit, then, just with rain water and a collection tank, or a small pump or human legs to carry it up every once in a while, you can have a fan that runs on zero fuel or electricity, just gravity and low pressures. That can help with air circulation and help a tiny bit with cooling during the summer (or at least the illusion of feeling cooler). This is really awesome and creative.
Or electricity
Very cool. I'd enjoy seeing some more refinements to the engine to reduce losses (more polishing of the piston and bore? More efficient diaphragm materials? Maybe route the exhaust air to act on the rear of the piston for a combined double-expansion double-acting action? (using the pressure left in the exhaust to help power the return stroke so less prop momentum is lost to that) and optimize the geometry. It's really entertaining to see you develop and test refinements.
A small air pump connected to the air tank outlet would let you push the water back up to the storage tank and save some trips up the stairs carrying water.
Honest question, But would potentially combining this with a double or even triple expansion styled air engine make it even more efficient?
No, the pressure isn't high enough. Steam engines didn't get double expansion until they got to several atm. The extra friction takes more power than it harvests at such low pressures.
Multiple expasion engines only used to prevent energy lost while steam expanding and temeprature drops. Or when small intake valve cutout is hard to implement. But air engine with piston-operated intake valve with automatical outake is not the case.
Another very cool project.
I could see this being combined with a flywheel / rain collector for a small generator.
You could use the motor you made for the e-bike, just re-wind the coils with more turns.
Also, I'm curious how your engine compares in efficiency to an air-hogs engine. Could they run on pressures that low?
Obviously it's Tom powered because you're carrying the water to the container.
He gets his energy from food, food grows from the sun, sun is nuclear fusion.
This entire system of engine+Tom+biosphere+sun is a nuclear fusion engine!
Maybe there's a way to add a float to release the water into a garden or something so that the tank can start a fresh cycle. Then it's like gravity fed irrigation combined with a fan.
Seems like a nice addition to a mini greenhouse
use the engine as a pump to force more water in the tank
Hey Tom awesome video as always! Looking at the design of the engine it seems it would be easy to make a radial version which would be cool if nothing else.
how are you still alive..
I think a bigger tube, even with the small inlet, would still help.
Flow rate is a function of diameter and pressure. At the top, you don't have high pressure, so your diameter should be sufficient to have a high flow rate. But at the bottom, the pressure is higher, so a size reduction and a smaller inlet at the bottom should suffice.
A bigger inlet will ofc still be better too. As that will cause less pressure differential at the bottom (thus less pressure loss before the flow rate can give you an equilibrium). But changing the top and tube alone will help.
You should try to "supercharge" the design by adding a pump to either increase the pressure in the hose,
Or add an secondary tank instead of the open upper reservoir, and in order to get it started have some kind of one way valve, and pump extra pressure into the upper reservoir.
Just a hint for cnc milling plastics is to fit an air nozzle to the mill head aimed at the tool to keep it cool. Stops all that softening and spring back that happens when the tool and the work get too hot.
In this design of engine, you could further reduce friction by an order of magnitude and lighten your rotating assembly by getting rid of the plastic piston and simply using a small piece of brass rod in a sleeve with your dome and pin affixed to it.
It would be cool to see this scaled up. I know it’s not really efficient or practical for much, but imagine using an engine like this made out of steel/aluminum parts with a large 100+ gal water tank at 50 feet plus, with a steel pressure chamber at the base.
I love the way you're mostly working on the floor - no fancy bench or expensive lab setup!! ;-))
Nice work! I wonder if lubing the engine would reduce friction and increase compression. Watching the video, I realized that the engine might work from pressured water too.
A propeller changing direction would make for a very sweaty pilot. Cool vid!
I always wondered about doing this with a ram pump. If you have property with a river or Creek with differences in elevation you could practically have free endless water and air pressure.
A great idea and good motivation to further improve your air piston design. With all these improvements ya aughta hook one up to a plane again and see how well it does
I would recommend for the acrylic below, to test if different figures help efficiency, I think that width is more important than the high.
You could try putting a one way valve at the water inlet and than pressurize the tank with a bike pump. That way it runs longer and the water can push in more pressure as it gets lower.
Very interesting Tom, you modifications to this simple air engine are inspired - Well done !
Nothing but smiles watching this video! What an achievement and a great watch - Thank you.
Definitely recommend getting a resin printer for precision jobs. All you need is a good mix of tough/flexible resing(~20% or os) with normal resin and you can print really strong parts, or even springs, that are very accurate. You could combine the two printing technologies. FDM for the bulk and structure, resin for precision parts.
I really hope we get to see this air engine in common ICE engine configurations-should theoretically be a walk in the park considering there's no valve train. I'd love to see efficiency compared as well
Chunking like a huge diesel engine. This is so badass. Thanks a million for sharing Tom.
OK, sorry if it has been suggested:
As it is a closed system and once the water is all "down stairs" you have to empty the cylinder and put it back upstairs.
Yes, this could be seen as "cheating", but why not add a third hole in the top of the cylinder and connect an air pump.
Then, when it is full of water you:
a) close the output to the engine
b) turn on the compressor and pump the water back upstairs.
Similar to how hydroelectric power stations work. Water being used in the daytime and pumped back up at night.
Just a thought.
That smile when you got downstairs and saw that it was working was one of the most genuine things I’ve ever seen on TH-cam
Lol its weird to see the tank "fill up" as it runs. Great video. Your air engine is a really cool design.
I am not sure what the appliance for this would be, but I like it!
You could get higher pressure by using a second cylinder instead of the upstairs bucket and then weigh it down.
You could have simply used the municipal water supply from your kitchen tap connected directly to your pressure tank. The supply is from tank which is much higher than that of your first floor.
In case you are not aware, a failing pressure vessel filled with gas is significantly more dangerous than one filled with water. That's why most tanks are hydrostatic tested. If a tank ruptures, the gas will continue to apply force while expanding until it equalizes with atmospheric pressure. This can produce significant acceleration of the tank fragments making them white dangerous. Meanwhile, since a fluid is effectively incompressible, when the container ruptures, there's almost no expansion, and very little force transferred to the fragments.