Stirlingengineforum.com

A wobble drive can be compact, http://en.wikipedia.org/wiki/Axial_engine . There is not the sliding friction of a cam and there is little side load from the conrods. No need for a whole disc, and a conical crank to one side is easier and less frictious than an angled "crank" through the mi...

On compact mechanism, I've posted toan other thread of yours: sinple, compact linear to rotary.

fulofhotair, LTD's use large diameters for large and simple heat exchange areas. HE is crucial for power in SE's. However, short and fat causes high conduction loss (and radiation loss in a hollow displacer, if no baffles), especially at high TD. For starters, look at engines which actually "go...

Hi Lucien01, thanks for the pics. So far, they have not helped me much. What is the difference between the flows in C1, C2 & C3? Is the distributor timed? What do you mean by "the surrounding"? The ambient atmosphere? I did not understand your earlier reference of connecting to it. I s...

Lucien01, I am not familiar enough with your thinking to learn much from your précis. I presume the figures are from your Sheet. You show how increasing mass flow reduces the dT. Do you mean you are extracting a mass flow of x% of Mercier’s system flow? Or do you mean you are circulating some of Mer...

JohnPain, I’d use thin stainless for the displacer - and for the cylinder. Thick sections and aluminium conduct heat to the cold end where it is difficult to remove. Some cold ends warm up and the engine slows – even petering out. Avoid clamp screws that pass from hot to cold plates. If the displace...

Lucien01, you show that the action has increased the source/sink dT from 300 to 467*k. That effect is much more than I expected, intuitively. It has also reduced the cold side to -29*C! Do you know of any tests to verify this practically? To save searching through your Sheet, have you assumed the fl...

Ha, ivspiano, everyone else has done the explanation of regeneration for me! A good design of regenerator consists of a stack of gauze discs. They break the airstream up into minute threads with plenty of impacts for good heat transfer. Also, the longitudinal conduction is quite low so little heat l...

Ivespiano, because the displacer is a loose fit, its cylinder does not need to be particularly round. So don't go to the cost and hassle of getting large clear tube. I now use foil wrapped, lapped and zapped round a handy former. Foils for baking or microwave bags will take quite a high temperature....

My user personal album won't accept a brief video so I've just uploaded Poppette on You Tube: http://www.youtube.com/watch?v=4l_ss9OcLdU. It is 4mm dia x 10mm high. It is running on a 70*C hotplate, but only just, so it is not really LTD although it uses similar constructional techniques. Its freque...

I don’t think Auroville’s Remy Mercier is claiming either an engine or a heat pump. What he is describing is a phenomenon that is an incidental by-product of regeneration that is going on in our engines anyway. Let his displacer piston be balanced by having a push rod at both ends. Then, internal pr...

Oops! When I said the displacement ratio of Senft's LTD engine was 15, I quoted the wrong engine. The ratio he uses in N-92 hand held engine (designed for 6degC dT) described in his LTD Stirling Engines, is over 150 - nearer the ratios I've used for really low dT. Sorry to be so misleading when I me...

This looks a bit like your engine: http://www.solarfire.org/SWEE-Technologies,129. It was $100, which sounds good for that quality, but you can get the latest prce here: http://www.alibaba.com/product-free/110643431/Stirling_Engine_Powered_Fan.html. The hot end is at flame temperature so soft solder...

Hi Paulie, I like tiny engines, too. Have you seen these? At the end, a tiddler is going fairly fast: http://www.youtube.com/watch?v=dICFVknQ7_Q Here’s some more: http://www.stirlingparadise.de/coll_schager/coll_schager.html. One is a “thumb nail sketch”: http://www.stirlingparadise.de/coll_schager/...

For LTD's I've used a thin wire (guitar string) push rod in a close-fitting tube (or even just a hole in the end plate where the conrod is long, allowing for the small rock). There was very little friction or leakage.