Stirlingengineforum.com

Hey guys.

Im new in this forum, but it seems like you know a lot about Stirling engines! - And im in a rather frustrating situation atm. Im at the first year of mechanical engineering. I have been given the task to build my own engine (i have to do some calculations on it, so i can find some effects and different volumes and create the P-v diagram aka. Schmidt analysis of the engine). My plan is to make a gamma version. My design is more or less like this one: http://www.epicphysics.com/wp-content/u ... Engine.jpg. My heat source will be a candle.
My problem is, that i haven't been given any information of how to optimize the engine. Since i have done some calculations on a perfect working trasparent stirling engine, i can logically see, that there must be some ratioes in the engine, which in some ways must be uptimized. So my question is, if you have any techniques to do so, or if you have any given ratioes?. This i would really appreciate! I've been given a power piston and a power cylinder with the inner diameter of 27mm and the hight of the cylider is 60 mm. So i will have to create the rest of the engine from these dimensions.
Thanks in advance!

Anders

Anders, The first ratio for Stirling Engines, power piston swept volume = 1, displacer swept volume 1.5. The next ratio as used by Robert Stirling, is the displacer, this should be a cylinder approximately three times the length of its diameter, a 1 mm clearance in the bore, and that or .5 mm more at each end, this is best made of thin walled stainless steel, although mild steel will do. Stainless steel should be used for the hot cap on the displacer cylinder, although my latest motor has mild steel as a temporary hot cap (I need a bit of stainless tube 40 mm bore, and .75 mm thick wall).
Remember, minimum friction, minimum leaks, not too much dead space, in that order, get the ratio right, and the timing right--- start at 90*. The simplest GAMMA motor is probably similar to my first one, a V type, these only need one pin on the crankshaft, the angle between the two cylinders can be adjusted by making the power cylinder able to be swung a few degrees either side of 90*. Ian S C

Hi Ian S C.

Thank you so much! - really appreciate, that you would take the time writing this! Was a big help for me!

Anders

Anders, sorry, I'v confused things a bit, I gave you the information required for a Stirling Engine that you could get some power from, I did not see the photo you had until today. Revision of ratios, power cylinder swept volume 1, displacer swept volume 10 to 20, say 1 : 20, the displacer could be 10 to 30 mm thick, don't think it really matters, but weight does, absolute minimum, the clearance at the side can be reasonably generous, 5 mm would do. There is another thread, just down the page a bit called "Why are their(should be 'there')no big Stirling Engines" By Adam Norris, have a look at the vidios. The first one from the USA is a much scaled up one similar to your photo, but solar powered, it has enough power to make it move, that's all. Ian S C