Displacer vs. Regenerator, LTD Stirling engines, side by side comparison. 

A link in the description opens to a forum with more in depth discussion of the subject, additional photos etc.. stirlingengineforum.com/viewtopic.php?f=1&t=2690&sid=9a1df9fa7fb4bf9bb36474463081beff The video was intended primarily for other forum members rather than a stand alone video. Hopefully in the future, when I get my workshop set up better, I can take better videos and find a video editor and computer. Right now I'm pretty limited to shooting short videos on my cell phone at the kitchen table and mostly rely on the forum for more in depth discussion. stirlingengineforum.com/viewtopic.php?f=1&t=2690&sid=9a1df9fa7fb4bf9bb36474463081beff

Thank you! The increase in speed is due to the steel wool Regenerator, which can be seen in more detail here: stirlingengineforum.com/viewtopic.php?f=1&t=2690 good advice from this video. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-gVU6uqn0cII.html to not compact the steel wool so it is transparent.

The engines are kits from this shop: www.stirlinghobbyshop.com/english/stirling-engine-solar-ltd-low-temperature-stirling-engine-ltd-stirling/ltd-stirling-engine-ja-828/#cc-m-product-9759217783 Some modifications were made; nylon bolts to replace steel bolts to cut down on conductive heat loss in both engines. In the one faster engine Regenerator added to foam displacer. I assembled the kits, but have no connection with the manufacturer.

The description reminds me of a TK Motors "hybrid" ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-CXsFNPmjluo.html A really amazing engine. Running: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-r9lYsW0Df08.html

Plastic sponge? What sort of plastic sponge exactly? Do you mean like for scrubbing pots and pans? I noticed that some types of plastic, like polyester or Nylon have a higher heat capacity than steel. Also some commercial model Stirling Engines have a sponge for a regenerator. Can you be more specific?

@@peoplesresearchcenter6184 Plastic sponge means as aquarium filter, rare open cell sponge. The displacer should light as possible. Styrofoam basic with few big circle cut off from that and put the sponge into the displacer material. As like here, but first the steel wool insert could work. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-CdX7hwjhgA4.html

@@AttilaBlade Thanks, though, there are several different open cell sponge-like aquarium filters made of different material. I had been considering trying aerogel. By "rare", do you mean natural sponge?

@@peoplesresearchcenter6184 No. The adjacent cell's distance is bigger, so the air could flow through easier.

The engine with the "regenerator" has holes in the displacer that are filled with some fine steel wool. Someone on the Stirling engine forum pointed out the experiment may be flawed, because there are no holes through the displacer of the unmodified engine. The higher speed of the "regenerator" engine might be a result of reduced resistance to air flow rather than "regeneration".

In theory, the regenerator (the faster one) is supposed to conserve heat, using heat more frugally while putting out more power. More heat gets converted to mechanical work or power output. In this experiment the slower engine actually ran a little longer however. It would require a lot more experimenting I think, to know anything for sure. The general consensus, though, seems to be that a regenerator (usually) improves the engine performance rather markedly. So the engine runs faster because less heat is wasted (in theory anyway).

@@peoplesresearchcenter6184 Yeah it's probably a combo of both being more efficient and more hungry. It looks to be going at least twice as fast.

did you read the description of the video

The one on the right that runs the fastest. The regenerator is built into the displacer. More info is posted on the Stirling engine forum

@@peoplesresearchcenter6184 hi thx for reply can we discuss more on any forum.actually iam working on it

@@salmantalash4515 Certainly. I started a thread on the topic of LTD type regenerators here: stirlingengineforum.com/viewtopic.php?f=1&t=2690 or if you prefer some other forum, just let me know, or right here is ok with me too. There is also other forums I post on. If you just search my name "Tom Booth" + "Stirling engine".

There are some pictures of the modified displacer (with regenerator) on the Stirling engine forum: stirlingengineforum.com/viewtopic.php?f=1&t=2690

Thank you for the analysis. Why do you think adding the steel wool to the displacer (engine on the right) results in higher RPM? Also, see this article: www.solarheatengines.com/2008/06/09/simple-stirling-1-performance-with-and-without-regenerator/