Neither Steam Nor Punk

March 4, 2009 10:06 AM

We've discussed the beautifully simple Stirling engine. Now witness the variety that a master craftsman (warning: German) can bring to this simple concept.
posted by DU (13 comments total)

(Dutch, not German. Good stuff, though, and thanks.)
posted by IndigoJones at 10:08 AM on March 4, 2009

D'oh, of course.
posted by DU at 10:08 AM on March 4, 2009

It's hard to pick a favorite because there are many different axes along which they can be compared. On the "simplicity" axis, this single moving part one stands out. (Depending on how you count parts, maybe 2 or 3.)
posted by DU at 10:13 AM on March 4, 2009

These remind me of the opening scene in Foucault's Pendulum where Casaubon is describing the machine room in the Musée des Arts et Métiers in Paris. Beautiful, thanks.
posted by nzero at 10:47 AM on March 4, 2009

Wow, these are really beautiful.

Now I secretly want a t-shirt which reads "Warning: German".
posted by quin at 11:46 AM on March 4, 2009

Thanks, DU, I'd forgotten how much I loved the Stirling engine. Its so much more elegant than the IC engine or Watt engine. Damn shame its been basically undeveloped since its conception.

I think the part that I absolutely love about it is that it works backwards. Put in heat and you get mechanical energy out, put in mechanical energy and you get cold out. It isn't exactly practical given our superior methods of refrigeration in the modern world, but its such an amazing thing.
posted by sotonohito at 12:00 PM on March 4, 2009

I'm a fracking idiot. Just finished reading, which I really should have done before posting, and found that the Stirling engine is used extensively in cryocooling because it'll cool to temperatures lower than those that a Rankine cycle can reach.

Not just colder, but 20% more energy efficient. I *LOVE* the Stirling cycle.
posted by sotonohito at 12:09 PM on March 4, 2009

There's been some development of it since then, but not quite enough to make it 100% viable. Or maybe I should say it's viable but not widespread. Amateur alternative energy enthusiasts (including myself) really love the Stirling because even boneheads (also including myself) can build one.

I think ultra-low cryogenics stuff actually uses stirlings for cooling because you aren't limited by a chemical reaction or phase change temperature. More muscle = more cooling (almost) all the way to 0 K.
posted by DU at 12:12 PM on March 4, 2009

Stirling engines are being used in solar energy generators built by Sandia National Labs. They are more efficient than solar cells.
posted by eye of newt at 3:49 PM on March 4, 2009

These engines must be ideal for pseudo-perpetual motion machines - if you can keep one end hot and one end cold, which could be as simple as one end in the sun, one end in deep shade like under a house, it could do a lot of useful things. I wonder why that sort of application doesn't see more use.
posted by aeschenkarnos at 6:00 PM on March 4, 2009

I wonder exactly the same. To the extent that that's exactly what I'm (slowly and mostly ineffectually) working on. I was thinking of putting the cold end underground rather than under a house and covering the hot end with a greenhouse-like arrangement, but basically the same idea.
posted by DU at 5:06 AM on March 5, 2009

I wonder exactly the same. To the extent that that's exactly what I'm (slowly and mostly ineffectually) working on. I was thinking of putting the cold end underground rather than under a house and covering the hot end with a greenhouse-like arrangement, but basically the same idea.

Like a reverse heat pump.
posted by atrazine at 6:30 AM on March 5, 2009

This thread has turned into my personal blog, unfortunately. Anyway: A Stirling is in fact a reverse heat pump. That's why you can use it as a cryocooler.
posted by DU at 8:56 AM on March 5, 2009