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LTD Stirling Engine

PostPosted: Thu Dec 31, 2009 7:17 am
by therightnee
hello everyone!

for the last three years now i've ben researching Stirling Engine
technology and I finally got around to building one. I decided to do
something on my own, but I modified the plans for Dr. Senft's N92 LTD
Stirling engine. At the moment the engine isn't running, so I have a
few questions.

below is a link to my designs:

1. I understand that flywheels are used to normalize the output speed
and to maintain the momentum of during the down stroke, but are they
essential in the build? Originally I was planning on using some sort
of compression spring to provide the return energy.

2. Is there a necessary displacer diameter relative to the chamber
diameter? The disc I cut is roughly 1/4 of an inch smaller in diameter
than my chamber, but I am wondering if there is an optimal size for
the displacer.

3. Are there any tips for a aspiring Stirling engine creator?


LTD Stirling Engine

PostPosted: Thu Dec 31, 2009 1:05 pm
by stan.hornbaker
Since Dr. Senft's N92 LTD Stirling engine is a model the Model Engine Forum would be the best place to find information, suggestions, and tips regarding Stirling models. It might be well worth your taking the time to wade through the good the bad and indifferent there.

Various methods have been used in place of flywheels, e.g. pendulums or movement of engine itself. Any model Stirling must be sealed air tight against any but a very small amount of leakage at the displacer gland. The piston should be an accurate smooth sliding fit in the cylinder, Graphite in Pyrex is excellent and available ready made from Dashpot Corp. as a sample and/or purchased. The piston should fall freely through a closed cylinder and fall slowly, 10 to 15 seconds, through a closed end cylinder.

For a first Stirling a replication of the original design without modifications is most likely to result in a nicely running engine. Once you have a running engine modifications/enhancements are icing on the cake.