Talk:Stirling engine/Archive 5

Action of a beta type Stirling engine
The animation is reverted in time. As it is now, the machine works as a heat pump, not termal machine. dima (talk) 05:04, 26 September 2008 (UTC)

Are you sure? I'm not an expert but the image seems ok. —Preceding unsigned comment added by 129.104.247.2 (talk) 10:53, 7 November 2009 (UTC)

Minto's Wheel considered as a rotary stirling engine?
is it fair to call a Minto wheel a "rotary stirling engine?" —Preceding unsigned comment added by 75.87.135.149 (talk) 05:07, 14 December 2009 (UTC)

Moon colonisation
The article Colonisation of the Moon says that stirling engines might have a place there. Should it be mentioned or at least linked to in this article? -- Cimon Avaro; on a pogostick. (talk) 11:23, 12 January 2009 (UTC)


 * How about as a "See also" link? – ukexpat (talk) 14:58, 12 January 2009 (UTC)

Aeolipile
Is a (solar-furnace powered) aeolipile not better (price/performance- than a stirling engine. Please include similarities and mention in article —Preceding unsigned comment added by 81.246.185.80 (talk) 15:08, 6 February 2009 (UTC)

Tags
User Cmlewis2 has recently added a number of tags or templates to this article indicating that major revisions are afoot. No such revisions are yet apparent and no response has been recieved to message on user's talk page. To my mind, the combined efforts of a number of individuals over the last 12 months or so has resulted in an informative, readable and well referenced article from the lede, up to and including most of section 4.1. Granted a little copy editing and general tidying might still be in order, but I don't see the need for major changes. Comments?Pv=mrt (talk) 08:48, 31 March 2009 (UTC)


 * I agree, User :Cmlewis2 only began editting on Wikipedia 2 days ago and seems to have gone headlong into criticism without opening a dilogue with existing editors here. If you read this Cmlewis2 can you let us know what changes you'd like to see. Lumos3 (talk) 21:31, 31 March 2009 (UTC)


 * May I then move for reversion of User :Cmlewis2's edit?Pv=mrt (talk) 08:09, 1 April 2009 (UTC)


 * The tags have been up for 3 days now with no comments here to support them so remove. Lumos3 (talk) 09:14, 1 April 2009 (UTC)

I believe the earlier placed tags of "multiple issues" and "insufficient inline citations" have now been addressed and can also be removed. Any comments? Lumos3 (talk) 09:19, 1 April 2009 (UTC)


 * I am puzzled by the insufficient/innapropriate/misinterpreted citations tags. I have access to a small but seminal library of Stirling engine related literature so if there are any specific issues of that sort, please identify and I will attempt to find a suitable ref or clarify an existing one - for the core subject and it's history anyway, I'm not wasting my time trying to track down stuff on esoteric possible applications like moon colonisation! If no specific issues are raised here within a reasonable time, then I suggest you go ahead and remove the tags.Pv=mrt (talk) 11:07, 1 April 2009 (UTC)


 * Now been a week with no comment so tags removed.Pv=mrt (talk) 09:00, 8 April 2009 (UTC)

Poorly sourced
Far too much of this article is unsourced or poorly sourced. I've tagged this article with refimprove and self-published tags. primarysources and unreliablesources also apply, but I think it would be better to concentrate on just the self-published articles first. --Ronz (talk) 17:06, 5 October 2009 (UTC)


 * Please identify which sources you consider to be of dubious quality and, if I have cited them, I will attempt to find better ones or justify use of the original.Pv=mrt (talk) 12:03, 6 October 2009 (UTC)


 * I guess this is true (as for many WP articles!), but most of the info given is actually in some of the books listed. I have many of them. They are however mostly not available online and some are even self-published as you say. This does not detract from their quality. I was a professional stirling engine engineer for some years but havn't written anything about this here. Hoever I did see lots of the things going on about 1995-2003. E.g. the flat-plate water pumps I put in (but have nothing to do with) do work and they are impressive. (However photovoltaic pumping is easier and probably cheaper, so they havn't caught on.) Anyway, I'll try to source some of the things from my books, thank you for giving this input. --Theosch (talk) 13:44, 6 October 2009 (UTC)

Please note that books (other than textbooks) are usually not considered reliable sources because of the lack of review.

Here are some references that appear self-published: --Ronz (talk) 16:39, 6 October 2009 (UTC)


 * Thank you. I've started replacing some of them. Some like Alan Organ are well-known professionals and self-publishing can be tolerated for these. --Theosch (talk) 21:05, 6 October 2009 (UTC)


 * I see Theosch has replaced ref to Walker's lecture notes with his later book - I assume wording of the definition of a Stirling cycle machine is the same (I have the notes but not the book), if so, please include the complete passage as in the previous ref.
 * The 1818 and all that material on AJO's Communicable Insight is largely covered in 'The Air Engine' book, but why air? is not and anyway, as Theosch observes, AJO is a well respected professional in the field and inclusion of his work however published should require no justification. On the same note, link to The Air Engine sleeve notes has been removed again thus reducing the value of this ref.
 * Hartford steam boiler ref was added when someone requested verification that exploding steam boilers were a significant problem in the early 19th century. I guess it could be considered biased as I believe Hartford is/was a boiler insurance company, but it is backed up by a ref from the American Society of Mechanical Engineers.
 * I have no direct knowledge of any of the other refs you mention.
 * BTW. I find the statement that books are not usually considered reliable sources rather extraordinary.Pv=mrt (talk) 09:12, 7 October 2009 (UTC)
 * Thanks for looking into these in more depth.
 * "I find the statement that books are not usually considered reliable sources rather extraordinary" See WP:RS. --Ronz (talk) 16:18, 7 October 2009 (UTC)
 * It's going to be a lot more work going through these. While they seem OK, I think there are too many references and some are "primary sources". Almost all of this article could be referenced by three or so books which are the "secondary sources" deemed most appropriate for WP. Pv=mrt, yes the wording is practically the same and I can put it back later. --Theosch (talk) 22:39, 7 October 2009 (UTC)
 * I've put the requested quotation back but am wondering why you need this, Pv=mrt.


 * Now a question regarding the system of references in this article. The references mostly refer to the bibliography. Why do we need this system, wouldn't the usual system of listing the complete article information in each reference be better? (Which would also mean removing some of the many similar references. E.g. Finkelstein and Organ are referenced about a dozen times. Do we need this much detail? --Theosch (talk) 17:32, 9 October 2009 (UTC)

The change to Harvard refs was made as part of a major reoganisation by headbomb earlier this year.81.134.14.178 (talk) 08:17, 12 October 2009 (UTC)

Alpha Sterling engine diagram
I'm sorry if i do something wrong, this is the first time i post in "discussion". I edited the explanation in the first picture of the Alpha Sterling engine diagram because it said that air continued to expand in the cold cilinder, which is wrong. I'm writing this because I believe there still is an issue with the "90 degrees behind" section, but I'm not sure how to word it correctly.

Tudy77 (talk) 18:49, 11 December 2009 (UTC)


 * No, it's not wrong. It is the cold cylinder, which is 90° behind the hot cylinder. The crankshaft moves clockwise, which means that any moving point on the crankshaft reaches the hot cylinder 90° sooner than the cold cylinder. I'm correcting this now. Ulrich Lukas —Preceding unsigned comment added by 79.221.191.184 (talk) 05:21, 4 March 2010 (UTC)


 * I do agree that the diagrams aren't completely clear (aldough they aren't wrong). I posted a list of changes at User_talk:Zephyris

"They are quiet"
"They are quieter, less polluting, gain efficiency...".

The "quiet" Stirling engine seems to be quoted many times by everyone talking about this engine, but I have yet to see a real quiet one or see a movie of it on you-tube. The ones I ever saw are all extremely noisy. פשוט pashute ♫ (talk) 15:34, 6 May 2010 (UTC)

Perhaps it would be better to say that they have the potential to be quieter than other prime movers. Eg. see http://www.kockums.se/en/products-services/submarines-systems/stirling-aip-system/Pv=mrt (talk) 11:11, 9 June 2010 (UTC)

Configurations
I propose to change the subtitles to
 * One-cylinder stirling engines
 * includes beta-stirling engine
 * Two-cylinder stirling engine
 * includes alpha-stirling engine, gamma-stirling engine

At present, its otherwise a bit unclear (ie I'm guessing the alpha configuraion is more efficient than the beta, yet it seems to come "after" the alpha so the opposite idea is projected.) The gamma-configuration is the least efficient.

Finally, I'm wondering whether the "Non-displacer stirling engine" actually exists (see http://auto.howstuffworks.com/stirling-engine2.htm ), or whether its just an image to make the functioning more clear. If it does exist, it should be mentioned here. KVDP (talk) 08:59, 8 June 2010 (UTC)


 * "I'm guessing"
 * That is a strong indication that you shouldn't introduce any more of your inaccurate guesses as changes to technical articles. Please stop adding errors across Wikipedia, it's getting to a level where it counts as vandalism. Andy Dingley (talk) 09:33, 8 June 2010 (UTC)


 * It seems you didn't read my post all that well Andy, the efficiency info isn't really that important, adding the alternative names as the header will already make the article more clear. Regardless, Andy, do you have some graphic skills to help us out improving the images; that way you can be sure I don't make anymore mistakes, and things will go a little smoother.

KVDP (talk) 07:04, 11 June 2010 (UTC)


 * Having looked at the 2nd (the beta) stirling engine image, it seems that this image is incorrect (alpha wasn't, only not clear enough). Take a look at http://wood-pellet-ireland.blogspot.com/2009/08/variations-on-there-of-stirling.html and http://www.vectorsite.net/tpecp_10.html The "regenerator" on the sides are clearly missing. Thinking about this some more, it seems that there is not regenerator for the power piston neither, this too is best added. I made an image at http://commons.wikimedia.org/wiki/File:Solar_pyramid_in_pit_concentrating_solar_plant_2.png which could be used as a template to rework the images noted (work quickly dough as I fear this image won't survive for long !)


 * Another thing we could change is the alpha stirling (since we'll need to update it anyhow). Rather than a 90° setup, we could use a 0° setup, similar as http://www.vectorsite.net/tpecp_10.html

KVDP (talk) 07:04, 11 June 2010 (UTC)


 * You seem to be getting yourself rather confused (although that in itself indicates some failings in the article). The classifications 'Alpha' 'Beta' and 'Gamma' are standard nomenclature for Stirling engine configurations, the number of cylinders is irrelevant for the purposes of classification (for instance a Rinia configuration engine is an Alpha with a minimum of four cylinders) and the regenerator is often omitted for clarity in diagrams that focus on configuration.
 * I'm not disputing that they are the standard names, I'm merely saying that it would be clearer to have level 3 headlines with "One cylinder", "two-cylinder stirling engine", ... rather than Alpha, Beta, Gamma, ... The exact names can then be mentioned in the text under the headline. This too was done at http://www.animatedengines.com/ross.shtml Omitting the functioning of the regenerator dough is best not done at the article, since we cannot expect that a reader already knows the standard functioning of (any) stirling engine.

91.182.139.105 (talk) 14:10, 11 June 2010 (UTC)
 * Dear KVDP, please sign in and then everyone can tell it is you, not just those who recognise your style and spelling.
 * This would be a very bad change (i.e. reverted on sight). It would be tantamount to WP:OR for once thing, apart from simply being wrong (multi-cylinder versions of any can be shown trivially). This is an encyclopedia, not a research notebook - we don't get to change accepted terminology (like Cornish engine) just because we think our personal view would be "better". Andy Dingley (talk) 14:37, 11 June 2010 (UTC)


 * The setup in the link you refer to as 'zero degree' still has a 90 degree or so phase difference, but this is achieved by using two cranks rather than angling the cylinders about a single crank. An engine with no phase difference would not work - the indicator diagram would tend towards a straight line with no enclosed are and thus no work!
 * I didn't get the exact name for this alpha stirling setup, but regardless of the name, the image at the linked page says it all.

91.182.139.105 (talk) 14:10, 11 June 2010 (UTC)


 * BTW. If you look at "Air Engines" by Finkelstein and Organ", you will find a neat demonstration that the Alpha and Beta configurations are in fact identical to each other but seen from a different frame of referance!Pv=mrt (talk) 10:45, 11 June 2010 (UTC)

Animations
Made 2 new animations: Note: first one will be renamed soon. Not sure whether animations will be accepted for use in the main article, but they're already useful nonetheless for anyone who wants to get a a bit more information on the exact workings. PNG-frames of image are available on request if someone also wants to make a animated png of the animation (perhaps with some improvements, since some of the text wobbles, ...) KVDP (talk) 07:06, 12 August 2010 (UTC)

Very good - I wouldn't know where to start! I'd be more than happy to see those in the article with a little cleaning up (don't quite get the external heat flow tags for instance) Pv=mrt (talk) 15:19, 16 August 2010 (UTC)

The Beta Sterling Engine has different sized pistons for hot and cold, should the Alpha Sterling Engine also have piston heads with different widths? If so is there an equation for the size ratios, possibly based on the temperature difference? Andrew Swallow (talk) 05:52, 7 November 2010 (UTC)

Quasiturbine engine
The Quasiturbine engine, mentioned under "Functional Description" > "Other types" > paragraph 2 does not seem to fit the description of a stirling engine as it is an internal combustion engine. Nohong (talk) 08:01, 24 December 2010 (UTC)

Assessment comment
Substituted at 22:08, 3 May 2016 (UTC)

Splitting section out
The article is now nearly 80k, so I reckon we should think about moving to a more summary-style layout and splitting sections out to dedicated articles. A good start would be the Applications section, which currently take up about the third of the article length, is pretty standalone, and would be given room to grow in a dedicated article. Thoughts? Chris Cunningham (not at work) - talk 13:40, 16 April 2009 (UTC)


 * Agreed, but probably for the wrong reasons. As I indicated in the 'Tags' thread above, I feel that the standard of the article falls off somewhat from section 4.2 onwards, so splitting off some of this material will a)stop it detracting from the 'good bits' and b)may be a trigger for improvement of the new sub-articles. I guess the key is getting the summery in the main article rightPv=mrt (talk) 12:26, 21 April 2009 (UTC)


 * As a non-expert, both in engines and Wikipedia editing, I'd like to see the "Applications" section stand, but keep the sction to the summary approach, so that both detailed or obscure material can be dealt with in dedicated articles (the possible use in moon colonies, for example, could be noted in one brief sentence, and a separate article if required would explain how, the pros and cons etc.) [Bruce, 31 May 2009]

Personally I don't think that splitting this is necessary. I've got a pretty archaic internet connection and 80k was completely manageable and internet gets faster every day it seems like. Almost every technology based wiki-page has an "Applications" subheading and I think it is very useful to have that information right there on the same page, particularly when talking about the Stirling engine since it's use may be making a comeback with hybrid technology. —Preceding unsigned comment added by 216.67.79.156 (talk) 22:06, 22 June 2010 (UTC)


 * Split has been done - Applications of the Stirling engine. The summary I have left behind is rather poor, and will need improving.  SilkTork  *YES! 00:30, 19 March 2011 (UTC)

Low temperature differential Stirling engine
Although it's not strictly a "type", with a Low temperature differential Stirling engine (LTD Striling), the pistons are made allot wider. See http://ir.canterbury.ac.nz/bitstream/10092/2916/1/thesis_fulltext.pdf —Preceding unsigned comment added by 81.242.234.187 (talk) 11:13, 2 March 2011 (UTC)
 * Nice try on the link, but it comes back bad...  TREKphiler   any time you're ready, Uhura  18:50, 2 March 2011 (UTC)


 * "The pistons" are not a lot wider - only the displacer piston is wider. Andy Dingley (talk) 01:35, 3 March 2011 (UTC)

Since it matters, the formulas to calculate the width of the pistons would be useful. Thank you. Andrew Swallow (talk) 13:48, 3 March 2011 (UTC)

Reference to be added; comment about regenerator
I suggest adding another reference to the Bibliography:

C.D. West, "Principles and Applications of Stirling Engines", Van Nostrand Reinhold, NY, 1986

Also:

In Allen J. Organ's book, "The Regenerator and the Stirling Engine", he presents a case as to the importance of the regenerator, which adds to the efficiency of the Stirling engine by recovering a portion of the waste heat. This reduces the need for both cooling and reheating the working fluid, increasing work efficiency. However, the downside of the book is that it is densly mathematical in its presentation, and the specific benefits of various regenerator concepts is not readily understandable.

One thing that the various graphics on the main Stirling engine page do not have, is the regenerator itself. It is not quite clear in Organ's book how the regenerator is sized, although there seems to be a sequence of calculations designed to do this.

In addition, Organ's book develops the idea of scaling a Stirling engine design by Similarity, as a way of sizing the various components in the engine. — Preceding unsigned comment added by John Fornaro (talk • contribs) 18:19, 12 April 2011 (UTC)

In addition to the graphics, the text in the abstract of the main Stirling engine page also does not include the regenerator. Down in the regenerator section, a distinct regenerator is identified as a distinguishing characteristic of a Sterling engine, so it would seem important enough to deserve mention in the initial description. The third paragraph discusses the cycle and it's efficiency, and would be a logical place to incorporate a reference to the regenerator..Dave b10 (talk) 19:16, 21 October 2011 (UTC)

combined heat and electric power
an ideal application is completely ignored. an SE could be part of an industrial water heater.Tthe cold sink of the sterling could be a preheat tank. CorvetteZ51 (talk) 03:50, 30 June 2011 (UTC)

theoretical efficiency
The article says (2100/11/21) "Theoretical thermal efficiency equals that of the hypothetical Carnot cycle". My understanding is that the Carnot cycle is for operation between 2 adiabats and 2 isotherms. The isochors of the ideal Stirling engine aren't adiabats: there is heat transfer on portions 4 and 2 of the cycle (see the pressure-volume graph at the "Theory" section). In the formula for efficiency, e = (work out)/(heat in), this extra heat lowers the theoretical efficiency. That is, in the Carnot engine there is heat transfer only along the isotherms, none along the adiabats. In the Stirling engine, there is heat transfer along the isotherms plus Q at constant volume = (# of moles)(molar specific heat at constant volume)(temperature difference) Is the claim that the heat in along portion 4 is of the same magnitude as the heat out along portion 2? Kinzele (talk) 16:20, 21 November 2011 (UTC)

DEKA's contribution
DEKA Research has been working to improve the performance of low-cost Stirling engines. Has this firm made any significant contributions to the field? If so, it deserves a mention in this article. 71.221.121.78 (talk) 04:51, 28 November 2011 (UTC)

Other gases
In his Stirling cycle engine experiments, the late professor D.H.Chaddock OBE had some success using CO2 as a gas medium. As this gas has been used in gas cooled nuclear reactors it seems a viable suggestion.AT Kunene (talk) 07:03, 13 February 2012 (UTC) -- Reply:

CO2 has a molecular-weight of about 44. Air's average molecular-weight is about 29. Hydrogen's molecular-weight is about 2. Low molecular-weight improves Stirling efficiency. CO2 doesn't share air's risk of combustion of lubricating-oil, but neither does helium, which has many times lower molecular-weight than that of CO2. The amount of helium needed for an engine is small, roughly-comparable to what is used in an ordinary small helium balloon. — Preceding unsigned comment added by 71.84.136.105 (talk) 16:23, 11 January 2021 (UTC)

Animated GIF is faulty, please fix
The Animated GIF jumps between cycles on the page can somebody fix this? it is very disturbing as it fails to show the complete cycle.Cheers Read-write-services (talk) 04:47, 16 February 2012 (UTC)

Hybrid applications
Stirlings are ideal for hybrid applictions where they only charge batteries or a hydraulic accumulator. The downside of cheap Stirlings to an IC engine is then irrelevant. Instant power and starting is not needed.194.83.172.121 (talk) 10:54, 18 May 2012 (UTC)

Downsides of Stirlings Misrepresented
Downside is larger size for equal power top an IC engine. Greater weight as well. The slow starting has been overcome, and the sluggish power delivery

But!!! A Stirling may be larger and weightier than an IC for the same HP, but the torque delivery means it needs no power sapping and weighty stepped gears transmission, negating the disadvantage in real vehicle installations. When in a direct drive configuration of course, which the auto industry is slowly moving away from with hybrids.194.83.172.121 (talk) 10:53, 18 May 2012 (UTC)

Counter-Rotating Ring Receiver Reactor Recuperator
Counter-Rotating Ring Receiver Reactor Recuperator has been mentioned in the see also section. This as it has been mentioned as a thermochemical analog to Stirling and Ericsson cycle heat engines  — Preceding unsigned comment added by 91.182.179.185 (talk) 08:14, 6 September 2012 (UTC)


 * I have removed it because current WP style does not have red links in the "see also" section. HumphreyW (talk) 11:00, 6 September 2012 (UTC)

Free piston Stirling engine operation
I have tried to understand how the Free piston Stirling engine works but the textual description is not self sufficient. It really needs a notated diagram, or sequence of diagrams, linked to the steps of the description. Roly (talk) 12:23, 5 October 2012 (UTC)