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Heavy or lightweight displaser for more horsepower?

Posted: Thu Jan 18, 2018 6:14 am
by Wellington
Hello all. i want to build a stirling that produces good horsepower. Should i use a light weight displacer or a heavy displacer?
Thanks All. Regards
Wellington.

Re: Heavy or lightweight displaser for more horsepower?

Posted: Thu Jan 18, 2018 2:58 pm
by Trevor
Hi Wellington
A displacer that is extra light weight is very beneficial. Make it light as possible yet sturdy and do not use aluminium as the displacer as in high heat they will melt or distort badly. Ian can show you some photos of what can happen using alloy as a displacer.
Trev

Re: Heavy or lightweight displaser for more horsepower?

Posted: Fri Jan 19, 2018 2:29 am
by Ian S C
Wellington, yes use light weight steel, or stainless steel. Weight just causes extra friction, also the thicker metal conducts heat along it faster than thin metal. The thin metal acts as a regenerator picking up and dropping heat as the air goes past.
As Trev says, don't use aluminium if you want any power out of the motor, it will work as long as you don't use too much heat.
Ian S C
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Re: Heavy or lightweight displaser for more horsepower?

Posted: Fri Jan 19, 2018 12:46 pm
by Wellington
Trevor wrote:Hi Wellington
A displacer that is extra light weight............
Trev
Thank Trevor. will steer clear of aluminium displacer.
regards
Wellington

Re: Heavy or lightweight displaser for more horsepower?

Posted: Fri Jan 19, 2018 12:48 pm
by Wellington
Ian S C wrote:Wellington, yes use light weight steel, or stainless steel. Weight just causes extra friction....................
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Yep. I imagine the friction would go up. On another note: I remember once seeing a german website which sold lots of different stirling engines but can no longer find it. Any ideas which website that might be?
Wellington

Re: Heavy or lightweight displaser for more horsepower?

Posted: Sat Jan 20, 2018 3:39 am
by Ian S C
I think the German outfit you are thinking of may be Bohm. I bought one from Jaycar a couple of years ago, looks ok, but a bit feable.
Ian S C
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