Woodburning Stove-top Fan school project

[rastAtsap]

Hi!
I guess I should introduce myself ay?, I'm Rich, a 23 year old student studying Mechanical Engineering Technology in New York, andd for my senior project I would love to build a Stirling engine. I have my teachers approval, and a general idea of what I want to make

This is my inspiration: http://www.youtube.com/watch?v=FDjEkOENzvg
and also http://www.youtube.com/watch?v=zxO5d0B9Gwg

I want it to be a machined work of art; smooth, quiet and efficient (with a hint of badass)

So I'm pretty much on step one here. I need a little jump start so I can start coming up with a design.
First off, I love having visible moving parts, is it feasible to make the cylinder out of glass?
Aside from that. I don't know how to figure out the temperature difference that the engine will run at. From my understandings with this information I can start to come up with the dimensions and volumes associated with the Stirling cycle.

[Ian S C]

Test 039 (640x480).jpg (111.2 KiB) Viewed 6034 times

rastATsap, I,v been trying for the last 20min to get an image from my album, to here, it won't go, so if you have a look you will find a picture of my stove top fan/motor, and some of the parts, any questions, I'll answer them, the piston is 35 mm dia, there thats a start. Ian S C There you are ,another ten min, and see what you get. Have a look at the album anyway.

[Jerry]

The displacer cylinder doesn't need to be perfectly machined, so any glass bottle of proper dimensions will do. It may take a few bottles to get the cutting process down, but it's pretty easy. A light score with a glass cutter, run the bottle over a candle flame for 90 seconds then ice, repeat the heat/ice till the bottle seperates. Then clean up the edges with wet sandpaper.

You'll need to get some empirical research done, taking temps of wood burning stove tops. Your cold side will remain a bit above room temperature, so long as the fan moves enough air. Next, you'll need to decide on an engine type, alpha, beta, or gamma. Let us know these details, and we can help you work the numbers through.

[fullofhotair]

I thought maybe hit some second hand stores and see if they have any old electric fans.You would have the shroud and blade already made.If the motor didnt work they would probably give you a good deal.I always liked the rounded heads with deep fins on the old motorcycles.That would make a cool cold side.You could electroplate any of the parts like chromed shroud or blade.Have you ever seen that heat tortured blue metal finish.It causes colored patterns.I always thought that was bad ass.And lastly how about building the engine right into the stove pipe a couple feet up.It would look like a real pro job.

[Bumpkin]

Fullofhotair, the stovepipe certainly has a lot of potential, but for code and safety reasons I'd stay away from using it - or at least I'd stay away from personally recommending it. I like that idea about motorcycle heads. They're laying in the weeds all around here and I never even thought about them. Two-stroke heads would make a clean conversion - handy bolt patterns and studs ready-made - if it's got a central sparkplug you could replace it with a bushing for a displacer rod - the sparkplug itself might make a neat bushing if you could figure out how to drill out the electrode…

[rastAtsap]

Awesome thanks for your input guys.Ian I love wooden fan, I come from family of private pilots, so that would be a neat touch. I'm pretty sure I'd go with that style of engine, as I cannot picture how another type would work over a stove, but I love the swinging arm type...makes it m
ore visual that it's pumping heat. I also have been thinking about changing the displacer design...I was thinking of having fins on both sides of the displacer, that interlock with the top and bottom to increase heat exchange surfaces, although I'm not sure how beneficial this would be.

[Ian S C]

On my stove-top, the base is a 8 mm thick disk of steel, and the displacer cylinder is a bit of chromed tube from a vaccum cleaner, the bottom end (hot), is an 1/8th inch disc welded in with the stick welder. Ian S C

[rastAtsap]

So to start, I need the stove top temperature? And id like to use glass bottle as the main cylinder, what's a reasonable maximum diameter so I can start hunting down a source for that, come up with a height and then start working on the machined parts

[Ian S C]

Somewhere on the net there is a detailed description of the build of a stove top fan motor, using the glass from a Coleman Lantern- the clear type not the frosted. The lamp glass is heat proof. you should find it at a camping store, or somewhere similar. Ian S C