i ahve made a lamina flow engine using glass syringe as piston not graphite....i did not connect the glass syringe to flywheel iam testing the engine without connecting the flywheel....the problem is when i start the engine the piston moves outwards faster but comes inwards slowly it is not giving a continuous oscillating movement i dont know what to do can anyone help me....
here is the pictures....if i connect to flywheel will it work or not....
http://picasaweb.google.com/undefinedga ... itledAlbum#
help needed (lamina flow engine)
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jesterthought
- Posts: 21
- Joined: Sun May 20, 2007 5:22 am
Re: help needed (lamina flow engine)
Hi ganuganu,
Your piston is probably forced out by the expanding air as you heat it. It is slower to return, I think, because the cooling is less intense. That is not related to the so-called "thermal lag".
I am interested because I, too, seek a simple way to free-up syringes. If you find how to reduce the piston diameter, and discover a dry lubricant, please let us know.
If untreated, your "piston" will be far too tight. The power developed by these engines is minute, so they can hardly overcome their own friction. That is why free graphite pistons are used.
Graphite also has a low coefficient of friction. Moreover, its low density reduces the side loading. (The engine would run better vertically, if you could heat it.) Most engines with flywheels also use long conrods to minimize the piston side loads.
Friction is the bugbear. I find that accepting some blow-by due to a running clearance is better than a piston which is binding, even slightly. Blow-by becomes less significant at higher speeds. If your engine will not run at low speed (or start) the leakage might be too high.
If you cannot turn and lap an accurate piston, try casting an epoxy one. Smear the bore smoothly with a candle, first, to ensure a small running clearance.
The thermal lag of your engine occurs in the restrictor (or in the connecting pipe). It is due to the slow heat exchange between the air and the wall. During the expansion stroke the core of the hot air flowing through the restrictor is only half cooled, so the pressure remains higher than during the compression stroke where the rest of its cooling occurs. That small volume change is said to be the primary driving force.
Another possible driving force is due to the heated air being promptly cooled in the unheated matrix during compression, while it gets a second charge when it expands out through the heated zone again during expansion. Here too, there is a small temperature difference which adds to the output power.
These temperature diferences cause much less volume change than the gross heating/cooling which moved your stiff piston, I think.
Jester.
Your piston is probably forced out by the expanding air as you heat it. It is slower to return, I think, because the cooling is less intense. That is not related to the so-called "thermal lag".
I am interested because I, too, seek a simple way to free-up syringes. If you find how to reduce the piston diameter, and discover a dry lubricant, please let us know.
If untreated, your "piston" will be far too tight. The power developed by these engines is minute, so they can hardly overcome their own friction. That is why free graphite pistons are used.
Graphite also has a low coefficient of friction. Moreover, its low density reduces the side loading. (The engine would run better vertically, if you could heat it.) Most engines with flywheels also use long conrods to minimize the piston side loads.
Friction is the bugbear. I find that accepting some blow-by due to a running clearance is better than a piston which is binding, even slightly. Blow-by becomes less significant at higher speeds. If your engine will not run at low speed (or start) the leakage might be too high.
If you cannot turn and lap an accurate piston, try casting an epoxy one. Smear the bore smoothly with a candle, first, to ensure a small running clearance.
The thermal lag of your engine occurs in the restrictor (or in the connecting pipe). It is due to the slow heat exchange between the air and the wall. During the expansion stroke the core of the hot air flowing through the restrictor is only half cooled, so the pressure remains higher than during the compression stroke where the rest of its cooling occurs. That small volume change is said to be the primary driving force.
Another possible driving force is due to the heated air being promptly cooled in the unheated matrix during compression, while it gets a second charge when it expands out through the heated zone again during expansion. Here too, there is a small temperature difference which adds to the output power.
These temperature diferences cause much less volume change than the gross heating/cooling which moved your stiff piston, I think.
Jester.
Re: help needed (lamina flow engine)
..........You got it half right. When they say to use a syringe for a lamina, they mean just the tube part! The plunger part is made to grip the inside of the tube so the liquid can be pushed out. Griping doesn't work here. You need a piston that slides in and out freely and also has a leakage free seal. I looked at your You Tube video, if your marble engine is using for the verticle cylinder a syringe with plunger then hook up your flywheel to see if it will carry over to help retract the plunger back to the heated side. 