I tried to build a lamina engine, and before I managed to melt the test tube I was using, I noticed the same phenomena of the self oscillating piston when the connecting rod slipped off the crank. I think this engine has good potential to be a very simple generator with a rare earth magnet in the piston and a coil wound around the cylinder. Frictionwise a vertical cylinder would be better I think, and with another magnet outside limiting the stroke so you don't accidentally make a cannon.
I like the magnets in sheep's clothing idea! I think you could do a similar thing with the dead area, just have a magnet on the piston and another one in the open end of the cylinder. If they are oriented to repel you can adjust the piston position easily.
This is a ThermoAcoustic engine, I believe. Stirling engines imply an orthogonal element. The frequency of your engine depends on the load or the weight of your piston, but there probably is a minimum and maximum weight for a stable operation. If it is too light, the frequency may be too high to allow the heat transfer to traverse from the high to the low temp sink so the Q will limit it. Higher frequency = shorter stroke length and too short a stroke will squash the temp differential...
I am playing with an idea of using a small diameter loudspeaker as the piston. If I mate the speaker (cone point towards engine) to a appropriate size funnel I can attach the funnel (ideally with a 6mm small end) to the hot tube with a silicone stopper. The shorter stroke of the speaker should allow higher speed operation and it already has a magnet and coil in position. Not optimized I'm sure, but it should be easy to tell if it is worth pursuing.
I would call it a free piston thermal acoustic Stirling engine. Must be interesting to make a design program for this. I'm sure the volumes, forces and speeds must be balanced in a certain way to let it resonate. It must be possible to make it double acting. I think you were very lucky to have the right dimensions to have it working. Thanks for sharing this.
This actually makes me think of one of teslas experiments with air pressure to make a resonant system. He made a piston that ran off of high pressure air, and had it's spring system made of air, because when he used a metal one it would break from fatigue in less than one day.
It is interesting that the hole size is so critical. If you had a screw that could block more or less of the hole maybe you could tune the hole size. It may be that when you put a load on the engine, the ideal hole size may be different.
very nice, I think the motor you built is a kind of thermo acoustic travelling wave engine, the frequency is established by the resonant frequency of the system piston (mass) and gas spring force constant. It would be wery interestinng to try to enprove the motor power by pressuryzing the wole system.
its elasto resisnant, the elastic quality of air pressure differencial, very cool demostration of it. take the nut off use a small neo magnet, and wrap a coil of wire arounf the cylinder tube, and light an led.
hmm, if you built this engine, I'm sure you know its name. This is called acoustic stirling engine/lamina flow stirling engine.... I am awed by the tight seal of the piston, great precision masterpiece. I do know that this kind of stirling engines are sold online with prices at least $70.
Oh, btw. You mentioned that if piston is to heavy it will not work. That is because piston itself perhaps has it's own resonant frequency. If so, then it will be good to experiment with different weight of the piston to match that two resonant frequencies: one of the hot side, and another of the piston itself. What you thing about that idea?
Really really nice experience! Can you give us some info about the relative size of "tube" cylindre and diaphragm bore? According to you why is this diaphragm an important feature of the engine? Would it run without it? or with different boring diametre? Did you try the same concept with an "both end" open tube and a "static piston" to allow you to "tune" and perhaps reach different freqencies?
Another excellent work, and amazing discovery. What about using copper pipe for piston area in order to encourage faster cooling (better heat transfer)? Okay, then it will be no transparent, but perhaps it may work better. What you think?
This has the potential to be a very low cost generator. Even if the efficiency is not great, if it gets heat from the sun or waste heat(cooking stoves, water heaters...) then that hardly matters. Cheapness rules!
Any chance you could put up some dimensions of your engine? Also is the small bubble on the end of the cylinder functional or just a by product of your choice in glassware?
it runs because the heat expands the air, the air is then spread over a larger area including a cooling area, the air temp drops, air contracts, piston moves inward, air is trapped in the heated sections and expands again. Air, all gases really, have a heat up / cool down time, that time creates the freq of the piston. Larger air volume, low freq, smaller faster. Hydrogen would have the fastest freq for equal dispacement engines.
Power is force x distance. Can you measure the force from the piston? This will let us calc the output power. Can you estimate the fuel flow so I can calc the input power? I've heard these things can be almost 40% efficient. Get a shaker flashlight and put the coil around the output to gather the output work.
Hi, Would this type of engine be scalable? Have you tried to make one larger (it wpaers that there is enough weight moving around to move a magnet though a coil.. Cheers
Beyond my understanding, but fascinating. Would it be possible to utilise the waste heat from, say, a domestic CH boiler and the reciprocating action being connected to magnets through a coil to produce enough power to light a whole bunch of the new high-intesity LCD's? (free house lighting??) I see there are torches that one charges by shaking a few times... that principle is what I have in mind. I'm sorry I took less-than-zero interest in physics at school now!
you can think of the piston in the tube as a non linear spring. hooke's law gives the resonant angular velocity of an ideal spring as square root of (spring constant k divided by mass m). Divide that by 2 pi to get frequency. but there is a counter play of the velocity of air itself and the standing waves generated by the half open pipe. thermal lag of heat transfer of gas and regenerator. cool little puzzle to solve with equations!
Looks like inverse pulse tube bur efficiency is very low for these if you could add displacer instead of that orifice efficiency should increase significantly
would your first engine run at all without the flywheel , i am currently trying to get one of these going i have followed exact plans and yet the piston does not oscillate at all and im wondering if this engine is likley to do anything at all when coupled with a flywheel?
You might be able to use it as an electrical generator by replacing the nut with a rare earth magnet and winding a coil of wire around the tube. Not that simple of course, since the energy required to induce the electricity would come out of the energy necessary to sustain oscillation .
This engine reminds me of a Tesla coil, with the weight of the piston (and any possible workload) being measured as impedance, and the amount of gas in the system and piston altitude governing resonant frequency.
Interesting, it looks like a Mason motor. If the piston were metal, you could use ferrofluid on the outside of it to get great compression and lower friction.
There does not seem to be a simple easily understood physical explanation for this type engine though the literature does offer more than sufficient highly mathematical analyses.. The application of heat to a mass of air or gas enclosed to allow vibration of the air or gas particles mostly in one direction results in the excitation of these particles more or less in a coherent manner. the rate of vibration is governed by the length of tube open at both ends. This vibration manifests as a sound. The tube must allow movement of air through it and this is made possible by mounting the tube vertically. The frequency of resonance depends upon the dimensions of the tube and not upon the degree of heat applied. If the tube is mounted horizontally there is no sound produced as there is no air movement. If a piston is provided at one end of the tube which is closed at the other, and this piston displaced intentionally, there is a movement of air which gradually builds up to a sound wave which of course cannot be heard as the tube is closed at both ends.But the sound wave does exist and manifests as a pressure wave. The variations of pressure on the piston results in oscillation of the piston.. at resonance there are relatively large fluctuations in pressure and to make this possible the piston must not be restricted in its movement to dampen the pressure wave. As the sound wave is at a relatively high frequency, the inertia of the piston cannot respond to this rate and so oscillates at a very low sub harmonic of the resonant frequency.. This is the only simple physical explanation possible and it could be valid. Please see videos titled. "using heat to produce sound". All the best and congratulations on your well made engine. Perhaps you could add a flywheel and actually measure torque and speed and so obtain output. Knowing the amount of fuel used per unit time you could obtain the input in calories, convert to watts or hp and obtain the efficiency of y our engine. This should be around 10 or 12%. All the very best to you , Sir.
Great engine! as far as I know only one similar example on youtube: search "mdevink pulse tube fluidine" Would it run verticaly? There is a great book from "Senft" dealing with ringbom engine that provide a lot dynamic data analysis that (probably) could be applied to your concept.
Stirling Engines are great. If you want to get the plans to build your own Stirling Engine and Combine it with solar Power - Go to Google and search for "Solar Stirling Info " Pick the first result
I tried to build a lamina engine, and before I managed to melt the test tube I was using, I noticed the same phenomena of the self oscillating piston when the connecting rod slipped off the crank. I think this engine has good potential to be a very simple generator with a rare earth magnet in the piston and a coil wound around the cylinder. Frictionwise a vertical cylinder would be better I think, and with another magnet outside limiting the stroke so you don't accidentally make a cannon.
I like the magnets in sheep's clothing idea! I think you could do a similar thing with the dead area, just have a magnet on the piston and another one in the open end of the cylinder. If they are oriented to repel you can adjust the piston position easily.
This is a ThermoAcoustic engine, I believe. Stirling engines imply an orthogonal element. The frequency of your engine depends on the load or the weight of your piston, but there probably is a minimum and maximum weight for a stable operation. If it is too light, the frequency may be too high to allow the heat transfer to traverse from the high to the low temp sink so the Q will limit it. Higher frequency = shorter stroke length and too short a stroke will squash the temp differential...
I am playing with an idea of using a small diameter loudspeaker as the piston. If I mate the speaker (cone point towards engine) to a appropriate size funnel I can attach the funnel (ideally with a 6mm small end) to the hot tube with a silicone stopper. The shorter stroke of the speaker should allow higher speed operation and it already has a magnet and coil in position. Not optimized I'm sure, but it should be easy to tell if it is worth pursuing.
I would call it a free piston thermal acoustic Stirling engine.
Must be interesting to make a design program for this. I'm sure the volumes, forces and speeds must be balanced in a certain way to let it resonate.
It must be possible to make it double acting.
I think you were very lucky to have the right dimensions to have it working.
Thanks for sharing this.
This actually makes me think of one of teslas experiments with air pressure to make a resonant system. He made a piston that ran off of high pressure air, and had it's spring system made of air, because when he used a metal one it would break from fatigue in less than one day.
It is interesting that the hole size is so critical. If you had a screw that could block more or less of the hole maybe you could tune the hole size. It may be that when you put a load on the engine, the ideal hole size may be different.
It's the resonant frequency of the bore/cylinder( not the piston) which matters. The standing-wave is "in" the bore.
very nice,
I think the motor you built is a kind of thermo acoustic travelling wave engine, the frequency is established by the resonant frequency of the system piston (mass) and gas spring force constant.
It would be wery interestinng to try to enprove the motor power by pressuryzing the wole system.
its elasto resisnant, the elastic quality of air pressure differencial, very cool demostration of it. take the nut off use a small neo magnet, and wrap a coil of wire arounf the cylinder tube, and light an led.
Very interesting and a nice commentary,thank you for sharing.
hmm, if you built this engine, I'm sure you know its name. This is called acoustic stirling engine/lamina flow stirling engine....
I am awed by the tight seal of the piston, great precision masterpiece. I do know that this kind of stirling engines are sold online with prices at least $70.
Oh, btw. You mentioned that if piston is to heavy it will not work. That is because piston itself perhaps has it's own resonant frequency. If so, then it will be good to experiment with different weight of the piston to match that two resonant frequencies: one of the hot side, and another of the piston itself. What you thing about that idea?
Really really nice experience! Can you give us some info about the relative size of "tube" cylindre and diaphragm bore?
According to you why is this diaphragm an important feature of the engine? Would it run without it? or with different boring diametre?
Did you try the same concept with an "both end" open tube and a "static piston" to allow you to "tune" and perhaps reach different freqencies?
Excellent! Very interesting.
Another excellent work, and amazing discovery. What about using copper pipe for piston area in order to encourage faster cooling (better heat transfer)? Okay, then it will be no transparent, but perhaps it may work better. What you think?
This has the potential to be a very low cost generator. Even if the efficiency is not great, if it gets heat from the sun or waste heat(cooking stoves, water heaters...) then that hardly matters. Cheapness rules!
Any chance you could put up some dimensions of your engine? Also is the small bubble on the end of the cylinder functional or just a by product of your choice in glassware?
it runs because the heat expands the air, the air is then spread over a larger area including a cooling area, the air temp drops, air contracts, piston moves inward, air is trapped in the heated sections and expands again. Air, all gases really, have a heat up / cool down time, that time creates the freq of the piston. Larger air volume, low freq, smaller faster. Hydrogen would have the fastest freq for equal dispacement engines.
Power is force x distance. Can you measure the force from the piston? This will let us calc the output power. Can you estimate the fuel flow so I can calc the input power? I've heard these things can be almost 40% efficient. Get a shaker flashlight and put the coil around the output to gather the output work.
Hi,
Would this type of engine be scalable? Have you tried to make one larger (it wpaers that there is enough weight moving around to move a magnet though a coil..
Cheers
Beyond my understanding, but fascinating. Would it be possible to utilise the waste heat from, say, a domestic CH boiler and the reciprocating action being connected to magnets through a coil to produce enough power to light a whole bunch of the new high-intesity LCD's? (free house lighting??) I see there are torches that one charges by shaking a few times... that principle is what I have in mind. I'm sorry I took less-than-zero interest in physics at school now!
Two connected together might make for an interesting method to convert waste heat into air-conditioning. It should be the same thermal cycle.
you can think of the piston in the tube as a non linear spring. hooke's law gives the resonant angular velocity of an ideal spring as square root of (spring constant k divided by mass m). Divide that by 2 pi to get frequency. but there is a counter play of the velocity of air itself and the standing waves generated by the half open pipe. thermal lag of heat transfer of gas and regenerator. cool little puzzle to solve with equations!
What is the size of the tubes you use. By the way I like the video.
@Mucktallbloke yep i'm pretty sure they are inversely proportional
Have you even seen a Stirling cryogenic cooler in operation that is turning air into liquid in an open room?
nice! put a magnet in the piston and copperwire around the glass. then u got electricity :)
This is fascinating. I would like to have a go myself. Can you point me in the right direction, please?
Looks like inverse pulse tube
bur efficiency is very low for these
if you could add displacer instead of that orifice efficiency should increase significantly
would your first engine run at all without the flywheel , i am currently trying to get one of these going i have followed exact plans and yet the piston does not oscillate at all and im wondering if this engine is likley to do anything at all when coupled with a flywheel?
where can I buy clips like that I've looked everywhere! what are they called?
You could generate electricity with this. Similar to those flashlights that you shake to power.
You might be able to use it as an electrical generator by replacing the nut with a rare earth magnet and winding a coil of wire around the tube. Not that simple of course, since the energy required to induce the electricity would come out of the energy necessary to sustain oscillation .
Hello, is it indispensable to have a reduction at the cylinder? or does it work without
greetz fron germany
Is there anywhere I can get a cross section of how exactly this works?
I'm still trying to get my head around this.
fascinating show.
This engine reminds me of a Tesla coil, with the weight of the piston (and any possible workload) being measured as impedance, and the amount of gas in the system and piston altitude governing resonant frequency.
sir can i use glass syringe as piston....
Care to share the plans for this?
the glass is not damaged by the heat
Interesting, it looks like a Mason motor. If the piston were metal, you could use ferrofluid on the outside of it to get great compression and lower friction.
There does not seem to be a simple easily understood physical explanation for this type engine though the literature does offer more than sufficient highly mathematical analyses.. The application of heat to a mass of air or gas enclosed to allow vibration of the air or gas particles mostly in one direction results in the excitation of these particles more or less in a coherent manner. the rate of vibration is governed by the length of tube open at both ends. This vibration manifests as a sound. The tube must allow movement of air through it and this is made possible by mounting the tube vertically. The frequency of resonance depends upon the dimensions of the tube and not upon the degree of heat applied. If the tube is mounted horizontally there is no sound produced as there is no air movement. If a piston is provided at one end of the tube which is closed at the other, and this piston displaced intentionally, there is a movement of air which gradually builds up to a sound wave which of course cannot be heard as the tube is closed at both ends.But the sound wave does exist and manifests as a pressure wave. The variations of pressure on the piston results in oscillation of the piston.. at resonance there are relatively large fluctuations in pressure and to make this possible the piston must not be restricted in its movement to dampen the pressure wave. As the sound wave is at a relatively high frequency, the inertia of the piston cannot respond to this rate and so oscillates at a very low sub harmonic of the resonant frequency.. This is the only simple physical explanation possible and it could be valid. Please see videos titled. "using heat to produce sound". All the best and congratulations on your well made engine. Perhaps you could add a flywheel and actually measure torque and speed and so obtain output. Knowing the amount of fuel used per unit time you could obtain the input in calories, convert to watts or hp and obtain the efficiency of y our engine. This should be around 10 or 12%. All the very best to you , Sir.
nasa was working in something like this man, very very similar, u are very very smart, i want to know about it :).... thank you for sharing...
hyy, can you tell me about the diameter OD and ID , for the piston and cold cylinder, a have two test tube but it's now precision..
thanks
Isn't that the answer to so many problems?
can you please send me the details dimensions of the engine
??? was ist vorn ander der Spitze ??? = ist das ein Luftventiel???????? What is the top of the front? = Is that an air valve ?????
Great engine!
as far as I know only one similar example on youtube: search "mdevink pulse tube fluidine"
Would it run verticaly? There is a great book from "Senft" dealing with ringbom engine that provide a lot dynamic data analysis that (probably) could be applied to your concept.
This is not a Stirling! A Stirling uses temperature differentials, this machine of yours uses acoustic waves to drive its piston.
i dont get how this work please some1 tell me
I think both ends should be cooled
LUBRICATION!!!
wow
Stirling Engines are great.
If you want to get the plans to build your own Stirling Engine
and Combine it with solar Power - Go to Google and search for
"Solar Stirling Info " Pick the first result
Cool
Hot
@@Virtualik
lol
bigger would move slower.
@Mucktallbloke yep i'm pretty sure they are inversely proportional