Water Air Engine

there are many ways to extract energy from water whether it be a water wheel or a more optimized turbine but i've never seen someone try to run an air powered engine using water well ignoring steam engines this video is sponsored by nordvpn more on them later without the use of coke mentos we can increase air pressure inside of a tank using a pump to push more and more air into a fixed volume or we can use a fixed amount of air and reduce the volume of the tank an easy way to shrink the volume of air in a tank is by filling the tank with water but one small problem is the water must be at the same pressure as the air or the air will just push it out however because water is roughly 830 times denser than air we can use this to our advantage if you swam down to a bottom of a pool you'll probably have felt the water pressure on your ears and no matter how large or small the pool was you'll feel the same pressure at the same depth this is because the static pressure of water is only relative to the depth and is essentially the weight of water above you pushing down and i plan to use this to create water pressure in my tank the plan is to put a tank of water in the loft of my house then run a tube downstairs to my tank full of air the vertical distance between these tanks is about 6.14 meters which means in theory when i let the water flow down the pipe the tank at the bottom should experience the pressure of being 6.14 meters under water which when we calculate the density of water multiplied by the acceleration due to gravity and the depth we should get around 0.6 bar or 8.7 psi of pressure then we can use this pressurized air to hopefully spin an air powered engine or is it now water powered so let's build this tank i could have opted for an easy choice of using a plastic drinks bottle as these are very cheap and easy to source and they can hold a lot of air pressure but i want something a bit more fancy made out of clear acrylic but as i've never made an acrylic pressure chamber before i need to do some calculations for example a 150 millimeter acrylic tube will require two plates on the end to hold the air inside and at just 0.6 bar the force pushing out on these two end plates is about 1060 newtons or equivalent to supporting a 108 kilogram weight so i used fusion 360 cad software to design the acrylic pressure chamber and i chose to use 15 millimeter thick sheets as the end plates after running a pressure simulation the thick end plates were probably a bit overkill but it allows me to cut this lip all the way around to give more surface area for gluing i've only ever cut plastic on my cnc router once before and it was the clear perspex type stuff you can buy at local stores for shed windows and i'm not sure if it was my cutting settings or the melting temperature of the plastic but it was a nightmare to cut so i crossed my fingers and attempted the acrylic lid which to my surprise cut really easily once finished it perfectly fit inside of the tube and it was now time to drill some holes and thread tap them for later adding some pneumatic fittings i then sanded down the gluing area on the tube and began mixing some epoxy resin which probably isn't the best glue option for acrylic but it's what i had laying around and it's pretty strong i also made sure to use plenty of it to fill all the gaps between the inner wall of the tube and the lip of the lid which got a bit messy but worked well in the end then we can fit a tube inlet on the bottom and a 3d printed stand to give enough clearance from the ground and on the top lid i can fit a pressure gauge and another tube outlet for the air supply to the engine the next step is to run a long tube all the way from the ground floor up 6 meters into my loft where i'll mount the water tank okay this is the first pressure test i've got five liters of water here and the container with the tube running downstairs gonna prop my phone up the problem also that i can't see if there's any leaks downstairs until i go down the stairs so i'm just gonna have to hope that this doesn't leak let's start pouring water's running down let's hope i don't just find a massive puddle downstairs so whilst we wait for the water to drain down let me tell you about the sponsor of this video nordvpn a vpn is great for internet security and privacy as it can hide your ip address as well as encrypt your data but nordvpn is more than just a vpn as they now offer thread protection which will guide your device from malicious websites malware and trackers even if you're not connected to a vpn but if you do want to use it as a vpn check out how easy this is to use let's say for example i want to watch shawshank redemption on netflix unfortunately it doesn't exist here on the uk netflix but i can simply open up nordvpn scroll over to the united states click here quick connect and as you can see it's there at the top click it click play and you can watch the whole movie in full hd due to their high speed connection for the price of a coffee the advantages that nordvpn gives you is an amazing deal and for a limited time only viewers of this channel can sign up for two years and get an extra month for free by clicking the link in the description down below plus nordvpn offers a 30-day money-back guarantee so why not give it a go still going down i might need to go check out what's going on downstairs this is making me a bit nervous let's go check out what's happening downstairs please don't be a league please don't be a leak oh no hang on hang on hang on hang on hang on there's no leaks and we've got five bar right i suppose i should go back upstairs and keep pouring nice i think that might be the water level seems to be staying still now so let's go check what the pressure is downstairs the pressure downstairs was about 0.57 bar or about 8.3 psi which is very close to the 0.6 bar that i originally calculated but is this really enough pressure to run an air powered engine well if you haven't seen my air powered engine videos before then you'll have no idea what i'm talking about so let's have a quick recap in november of 2017 i 3d printed my first air engine that was based off the old air hogs engines and although it did run it was extremely inefficient so in april of 2018 i built a new engine that used a square piston and a cam and pushrod design which was more reliable than my first engine but still quite inefficient as it was very difficult to seal the piston to the cylinder without lots of friction then two and a half years later in november of 2020 i came up with a completely new design that removed the need for an airtight piston by using a diaphragm and a new inlet valve that removes the need for any push rod valves and after refining the design way too many times it outperformed the previous best air engine by a factor of five and could also run at pressures as low as 0.7 bar or about 10 psi but will it work with my new pressure tank not quite and this reveals a problem that i hadn't previously considered not only do i need an engine to work at 0.6 bar but i also need to consider the flow rate of the water into the tank if i release all of the pressurized air the tank takes about a minute and 20 seconds to fill back up to full pressure again and it's too late to increase the diameter of the tubing as that would require new holes to be drilled for larger fittings so although i'd hoped that the engine would run at 0.6 bar which is not that much lower than the 0.7 bar that it previously worked at in reality it needs to run at much lower pressure so the first modification i made was to increase the diameter of the diaphragm within the engine as this will increase the area that the air can push against hopefully allowing lower pressures to apply more force to the piston and to my surprise it actually worked really well [Applause] at least down to about 0.3 bar when the engine would stop and i would have to wait for the pressure to build back up again the obvious next step would be to build an engine with an even larger diaphragm to run at lower pressure but there's a small problem because the design of the cylinder requires this cone section to allow for the diaphragm to expand it means the piston has very little support when it reaches the top of the stroke and making the diaphragm larger would mean increasing the unsupported distance for the piston which means the piston needs to be longer and so does the cylinder which will probably just increase friction also the crank case and crankshaft needs to be longer to avoid the propeller from hitting the cylinder so instead of completely redesigning the engine i decided to try tweaking a few things on the current engine the first being the ball valve that lets the air into the engine when 3d printing the cylinder head the printer often leaves small blobs of plastic as it moves on to the next layer and this means the o-ring used to seal the ball valve doesn't fit perfectly which isn't an issue at much higher pressures that i normally run the engines at due to the extra force pushing the o-ring into any small gaps but at these lower pressures if the ball doesn't perfectly sit on the o-ring it'll leak enough air to drop the pressure in the tank by almost half a bar to fix this i used my soldering heat gun to soften the plastic inside of the cylinder head and then push the o-ring and ball into position to mould the plastic around it which achieved a much better seal i then made sure everything in the engine was running as smooth as possible by sanding down any tight spots in the cylinder and aligning the diaphragm as best as i could and the engine now sounds much smoother but it's spinning way faster than it needs to be and running out of air so i took the piston out and shortened the small pin that opens the inlet valve which will hopefully reduce the amount of air that enters the engine per rotation almost like lowering the throttle this reduced the pressure at a much slower rate and the tank started to hold a constant pressure at just over 0.4 bar which made me incredibly excited no don't stop i thought we had a continuously running one then so i emptied the tank carried the water back upstairs and crossed my fingers for another run no i then realized that clicking noise you can hear was actually a huge amount of play in the crankshaft which i think throws the piston off center when it's unsupported by the cylinder so i remove this plate with a small spacer mounted the engine on a solid stand and attempted another full tank run the engine was off to a smooth start and took around 50 seconds to stabilize the tank pressure at around 0.45 bar then it's about 2 minutes and 10 seconds into the run the engine suddenly dropped in rpm as the pressure reduced but somehow the lower rpm allowed the tank to fill back up to pressure and the engine rpm increased again then at 3 minutes and 30 seconds into the run the engine nearly came to a complete stop multiple times before switching direction which again allowed the pressure in the tank to rise at this point there is so little air left in the tank that each breath of air that the engine takes will reduce the pressure by a huge amount so it struggles to keep the pressure constant and as the water reached the top of the tank i cut it off early to prevent the engine from drowning itself [Music] we did it we actually did it oh no don't get water in the engine all them i can't believe that actually worked not only was that the lowest pressure any of my engines have run at but it was also the longest run time ever had out of an engine with such a small amount of air with a total run time of four minutes and 42 seconds running just on the pressure created from a water tank in my roof i hope you found this interesting and uh i'll see you the next one thanks for watching

Channel: Tom Stanton

Views: 1,422,538

Keywords:

Id: 1Zf_2CZV6Zw

Length: 14min 41sec (881 seconds)

Published: Fri Mar 25 2022