Laminar flow engine

Conventional Stirling engines require a displacer chamber with a piston driven off the crank to move the air from the cold to the hot side of the displacer chamber. Ringbom realized that the displacer piston could be driven directly by the differing gas pressures and the design simplified so no connection of the displacer piston to the crank would be required.

Here's a video of one of my Ringbom engines in operation. The noisy thing popping up and down is the free-running displacer. This engine has a tiny water pump at the top driven off the crank to supply cooling water to the cold side of the displacer chamber.

https://www.youtube.com/watch?v=RcHAnVB-knE

Then some clever monkey invented the laminar flow version of a Stirling engine. This design has the ultimate simplification of the displacer chamber/piston; it simply isn't there.

I built a prototype just to see if I could make it run. Here's the result...

https://www.youtube.com/watch?v=3DF9gNCavKs

Note that the engine has only one moving part - the piston. There are no valves, no displacer, just a pyrex test tube with some pot scrubber in it and a chamber to house the piston. Power output is too low to make the engine practical but that doesn't bother me. It's enough that the thing runs at all - a constant source of astonishment for me.

This is interesting! Good work!