Beta Stirling Engines for Power Production

[callas.christina]

Hi all,

I'm in the process of designing a Beta Stirling engine to produce 50-
100W of electrical power. I was wondering if anyone knew of general
sizing rules (diameter, height,stroke length etc) for the pistons
and cylinder. I've found a general rule of thumb for Gamma engines
but I don't think it really applies to Betas becaue of the
overlapping swept volumes. All of the engine plans specs I've been
able to look at are slightly over-square but that's about all I've
been able to get from them. I've bought The Regenerator and the
Stirling Engine by Alan Organ which helpful for the thermodynamic
analysis but not really for sizing. If anyone has any suggestions
for engine proportions or resources they'd be much appreciated.

Thanks,

Christina

[stan.hornbaker]

Christina: 50 - 100W is too much for an LTD Stirling. For an interim design the temperatures of the heat source and heat sink required may not be readily supplied......
Why a beta design?..... Is this an absolute necessity or an academic requirement?.....
What is the end application for the output?..... To my knowledge there is little if any information available on exactly knowing how to design and build any kind of Stirling engine. All of the books speak in generalities. Suggest you get a copy of Allan Organ's latest book "The Air Engine: Stirling Cycle Power for a Sustainable Future" via interlibrary loan if at all possible. The price is prohibitive for anyone without unlimited funds......Check the links to Penn State and Ohio Univ. at

[callas.christina]

There is no requirement for my team and I to build a Beta engine it had just come out ahead of the others. The end goal of the project is to use the engine for an appropriate technology project. The Alpha design was rejected largely because of the increased wear of hot, moving seals. The Gamma design was thought to lack the power for size we're looking for. We're slightly limited on the cylinder size because we're planning on using a cook stove as the hot sink. This should give us a significant temperature difference.

We've researched previous appropriate technology Stirling efforts such as the St-5 and work by Merrick Lockwood but the power output in these applications was much higher. I do realize that Stirling design involves a lot of prototyping and testing I was just looking for some basic guiding on component proportions. I'll look into Alan Organ's new book but please let me know if you have any other advice.

Thanks,

Christina

Subject: Response to Beta Stirling Engines for Power Production

Christina: 50 - 100W is too much for an LTD Stirling. For an interim design the
temperatures of the heat source and heat sink required may not be readily
supplied......
Why a beta design?..... Is this an absolute necessity or an academic
requirement?.....
What is the end application for the output?..... To my knowledge there is
little if any information available on exactly knowing how to design and build
any kind of Stirling engine. All of the books speak in generalities. Suggest
you get a copy of Allan Organ's latest book "The Air Engine: Stirling Cycle
Power for a Sustainable Future" via interlibrary loan if at all possible. The
price is prohibitive for anyone without unlimited funds......Check the links to
Penn State and Ohio Univ. at

[stan.hornbaker]

The folks that design successful Stirling engines for commercial use are not likely to share their proprietary information. Phillips published a book on Stirling engines as did NASA. These are no longer in print nor available.

Your team might take a look at the 2.5-HP Dual Stirling engine built by Jim Symanski (deceased) shown on his son's Justin Symanski's web site at and follow all of the links to the Stirling and Hot Air Engines. The engine on the starting page was built from a photograph using junk parts collected along the mountain roads near Jim's shop. The shop and all the machine tools were run by that engine via belts and overhead pulleys!

[stan.hornbaker]

Allan J. Organ's New Web Site is now up and running at:
http://web.me.com/allan.j.o/Communicable_Insight/Communicable_Insight.html
He provides the latest information available on the viability and
design of Stirling engines.
It appears he is hint for others with Stirling expertise to join him in the design of the ultimate Stirling engine.