It's still under development (expect low performance for cost) but it is functional and has great potential for both simple construction and for later efficiency.
This guy has been building experimental sterling engines for some time but he's not an expert in all fields, and needs support of others in computational fluid dynamics, linear generator design, and heater head design.
However, he knows enough and is bold enough to have built and shared full designs for one that works. The next steps are to test and refine the design until it's efficient enough to be a good offgrid generator, which is his stated goal.
What is a thermoacoustic sterling engine and how does it differ from a normal sterling engine? This uses the same sterling cycle as other sterling engines, so it functions on the basis of the expansion of heated air moving a piston. It has the same generous fuel agnostic benefit that most external heat engines have. It could be run on anything that can heat it, so wood, biogas, woodgas, normal fuels, concentrated solar, anything.
However, the thermoacoustic engine simplifies the usual two piston sterling design. Normally you need a power piston to extract work from the engine and a second regenerator piston to push the hot air back through the engine. By modeling the interior of the engine carefully, you can use the principle of thermoacoustics (air temperature gradients creating pressure waves) to create a pressure wave inside the engine. If you design your engine space right, you can ensure that wave feeds on itself and gets stronger. This pressure wave feeds on the heat being added to the engine and becomes stronger as it bounces back and forth inside the engine cavity.
The result of creating a pressure wave inside your engine is that you no longer need a second piston to push the hot air into the cool side of the engine and back. The pressure wave does that.
As a result you have much fewer moving parts, just one power piston and thats it. This simplifies manufacturing, reduces cost, and improves theoretical efficiency. However, you need some complicated computer modeling to design one and previously it had been the province of NASA and others (NASA recently cancelled their very impressive thermoacoustic engine design)
This youtube channel has built one and is asking for our help improving its output.
Here are his two videos showing the heater core and the feedback piping
Heater core:
https://www.youtube.com/watch?v=ivyMKqm2LOU
Feedback piping:
https://www.youtube.com/watch?v=2BYy7IyJ8SQ
Basic channel:
https://www.youtube.com/@myengines2443/videos
