Lamina Flow Stirling Engine Anyone?

Question

So I found this and I need the materials:

http://www.stirlingengines.org.uk/thermo/lamina.html

Am I basically good so far?

Materials:

1. Glass Pyrex tube (where scourer will go, heat will build up, etc.)

2. cylinder (where the piston will slide). Brass, steel, glass, same pyrex tube, i don't know.

3. graphite piston.

4. stainless steel pot scourer(retains heat).

5. flywheel.

the rest is simple. (candle, etc.)

So where can I get all of these and approx how much will it cost?

Also please correct the list if you think something could be improved or changed.

Additional questions: What cylinder should I go with? Which one is effective, easy to obtain, and not too expensive?

How much should the flywheel weigh? I heard it has to be kinda heavy.

Also feel free to add details on if there's another important thing I need, building one, how difficult it will be, and how much time it will take.

I'm 14 and I think this is a good, easy engine for a beginner like me. Right?

Answer 1

Perhaps try asking at the chemistry department of a school/local college where they get their glassware from. perhaps you would be able use a test-tube, or a small flask to hold the re-generator stack. Don't know about pressure capability though (round bottom flask perhaps?)

I'd probably use a metal tube to form the cylinder, perhaps an off cut of plumbing pipe would do, You want a nice smooth surface (very time consuming/a nightmare to make such surface in glass)

I'd join the glass using some-kind of adhesive (the O rings are purely for sealing, not to accommodate movement)

Shouldn't get too hot with a candle. High temp silcones can go up to 300 deg C I think, don't know about epoxy, but it's probably higher (if not exposed to air) and should form a good fixed seal (just watch out for the metal expanding when it gets hot, it could end up cracking the Pyrex tube. Maybe be better to slot the glass INTO (rather than around) the metal tube.

Think the piston was speced as being a block of graphite as that would be self-lubricating. Maybe somethings to do with heat conduction, but I'm not sure. perhaps place some large O rings on the inside of the cylinder, then cover the (inside) of the tube with cling film. Then use the tube to cast a "plug" of epoxy in that end. If all goes well you should be able to pull the plug out, and remove the cling film. If all goes right, you've got a piston, and the O rings will form what amount to piston rings. Doubt the engines RPM will that high, so they should last some time before needing replaced.

A flywheel, is just any "large" wheel. How much angular momentum you need to be able to store (therefore size) depends very on how much/often the piston "charges" it up. Perhaps take a disk of wood/metal and affix lead weights on the its circumference to make a heaver duty fly wheel.

You could combine the crank-shaft and flywheel, by placing a pin on the flywheel, and having the piston rod drive it directly. Saves having a separate crankshaft on a single cylinder engine.

If you have two pistons the engine will be a lot smoother. If the pistons have enough force, the engine may well be also be able to start itself (without having to give the flywheel a push start) Just place the pistons at right angles to each other

Any ideas as to you choice of working fluid? perhaps simply use air maybe adding a little water could make it better. (maybe have a tap on the side of the tube so you can change fluids to see what difference it makes)

Good Luck.

If you can get the parts/figure out how to make them, it seems an ideal engine for a beginner.

Answer 2

I have no clue where to get all that stuff, but a quick search should find it.

Don't use glass for the cylinder, though.  Steel or brass, not glass.  Glass, oddly enough, will present too much friction.  Hmmm.  With a graphite piston?  Maybe not.  Dunno where you'd get one, though.

I think you'll get more info by using a search engine than by asking here, though.  Try it! What have you got to lose?

Sounds like a fun project!

Answer 3

These are interesting little engines. they do require a lot of tinkering to keep them running as many things effect them. These things were made in the late 1800's and there is a lot of info on them. I seen one that uses a bellows set up (no pistons)and the crank was also the flywheel

Answer 4

These guys are machinists. Unless you have access to a machine shop, you're in big trouble.

I would check "gas springs" for graphite pistons and matching cylinders. You should be able to get one from a junkyard real cheap. They are used to hold open hatchbacks and some hoods. They are high pressure though, so the bore is on the small side.