Stirlingengineforum.com

I wonder if 3D printing could be used to make every Stirling Engine part out of Tungsten. That would allow for operation at extremely high temperatures and the 3D printing may provide extremely good tolerances.

Maybe my question doesn't even make sense. With a 100% efficient regenerator and a 100% efficient mechanism, deviations from the ideal stirling cycle may not reduce efficiency. However, I'm not sure about this.

I wonder if this proposed design reduces the regenerator's dead space or simply shifts the dead space to inside the displacer.

'In particular, Pu-238 fuel, which generates about half a kilowatt of heat per kilogram of isotope, has been used to power space missions' That's from the article vamoose linked. I never realized plutonium had so little energy. I guess its the only option without oxygen or solar, when too far from t...

Does anyone know what percentage of the Ideal Stirling cycle can actually be harnessed? Have any real world devices managed to harness more than 90% of the ideal Stirling cycle? Clearly, a sinusoidal piston motion is problematic to harnessing more of the ideal stirling cycle. Can other mechanisms ha...

Sumit, If you're interested in efficiency, you may want to check out the following paper. http://www.readanybook.com/ts-3-thermodynamic-analysis-of-a-stirling-engine-including-dead-volumes-of-hot-space-cold-space-and-regenerator-pdf-i284489 Dead space plays a huge role in engine efficiency, and Senf...

One could try self lubricating carbon graphite rings with a chrome plated cylinder. Several companies sell these. Some of the very long lasting Free Piston Stirling Engines use gas bearings. These are essentially very small notches that allow for a very small layer of air to pass on either side of t...

All dead space reduces the thermodynamic efficiency of a stirling engine. However, hot dead space is required for the heater tubes in order to allow for a thermodynamically efficient transfer of heat into the working gas. Instead of using heater tubes, is it possible to use a displacer which looks l...

What is the most efficient Stirling Engine that has ever been built? Has anyone ever crossed the 40% mark when converting thermaal energy into mechanical energy?

The most efficient engines I've seen are from SunPower, which seem to hold the record at 36%.

From a theoretical perspective, beta stirling engines have better efficiencies because they reduce the dead space. According to this link from SunPower http://www.sunpowerinc.com/library/pdf/productlit/Engine%20Brochure.pdf their free piston beta stirling engines have an efficiency of 36% when the T...

A lot of the information that NASA has developed is available in research articles and books. For example, work on the advanaced regenerators is available in the book Stirling Convertor Regenerators.

rustybarrel, yes. even water exists as a supercritical fluid at very high pressures and temperatures. The main reason I was interested in supercritical CO2 is that the supercritical fluid occurs at lower pressures, which makes it more practical to actually use. Furthermore, work on Brayton engines i...

NerdyEE, I believe superfluid helium is different from a supercritical fluid(or supercritical helium). I believe superfluid helium only exists at very low temperatures, which makes it useless for Stirling engines. However, supercritical fluids exist at high temperatures, which allow them to be used ...

According to Wikipedia, supercritical fluids have between 5 and 10 times the viscosity of gases.

Have Stirling Engines that utilize a supercritical fluid as the working gas been built? Supercritical fluids are dense compared to gases and less dense than liquids. Supercritical fluids share many characteristics of gases and typically have a very high thermal conductivity and heat capacity. Superc...