The thermo-acoustic hot air engine also known as Lamina Flow Beta Stirling engine. This engine does have only one piston, two cold sides and one hot side. Is a very simple devices for converting heat into motion.
The history of thermoacoustic hot air engines start about 1887, where Lord Rayleigh discusses the possibility of pumping heat with sound. Little further research occurred until Rott's work in 1969.
A very simple thermoacoustic hot air engine is the Rijke tube invented/discovered by Pieter Rijke, that converts some heat into acoustic energy.
An older thermoacoustic hot air engine, where the speaker is replaced by a working piston, is the Lamina Flow engine or Lamina Flow Beta Stirling engine
The heat to be applied exactly where the mesh ends inside the tube. When the air inside the tube heats, it expands and cools down, then it heats again and the cycle repeats. At the beginning, the air is not hot enough so the oscillation is slow and weak. When the frequency of the oscillation is matched by the flyweel, it starts rotating. When more heat is applied, the frequency in the engine increases.
This thermo-acoustic hot air engine is a powered by an alcohol burner. Firstly, light the wick, & then make sure you give it a good minute or so to heat up as well. Try to give a little push to the flywheel which is strong enough to coast the parts for several cycles. After a few seconds the flywheel will perform a full revolution and continuing running on its own. The engine can performs in 2 directions, clockwise & also counterclockwise.
Mat : Wooden base , Glasstube , Steel wool & aluminium parts.