Talk:Stirling engine/Archive 2

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[edit] Closed cycle steam engines

Closed cycle steam engines do not recycle their working fluid each cycle but through a condenser and boiler which are external to the cylinder and recycling takes many engine cycles. This distinction is important as the Stirling engine is the only form which recycles the gas within the cylinder at each stroke. Lumos3 00:24, 26 February 2007 (UTC)

Lumos3, You make a point, and if you choose to draw your "control-volume" around the cylinder then I suppose you're correct. So, perhaps the real question is: Does an engine consist of just the cylinder and nothing but the cylinder? I think one could make arguments both ways. Anyhow, the way I learned thermo is that the term "open-cycle" means that the working fluid is open to the atmosphere. So when you mention an "open-cycle steam engine", I picture an engine with a large supply of water that is venting steam to the atmosphere. However, if the heat-engine system contains a condensor, and you trace the path of the working fluid (which may pass out of the cylinder), then it is technically a closed-cycle. Whether you agree with it or not, for the sake of the article I think one has to accept the terminology and conventions as they have been defined by the scientific community.

Most people don't know what a Stirling Engine is, so the aim of the article should be to educate the reader on that topic. The first distinction of a Stirling engine is that it is an "external combustion engine". Now, since the most common type of "external combustion engine" is the steam turbine, I think that is the most important comparison. Anyway, the article is about Stirling engines, not steam engines, so this really isn't the proper forum to debate whether the steam engine is an open-cycle or closed-cycle. With all due respect, IMHO, if it's really that important to you, then maybe you should bring the issue to the Steam engine page. Mikiemike 18:47, 13 March 2007 (UTC)

Lumos can be fun, huh?  :) But, perhaps he can chime in on this question I have, which is, I think, important to the discussion of the Stirling engine.

Currrently, there are a number of sites in the world that produce geothermal energy using steam generation. I tried to find comparisions between available practical Stirling engines and the vaious deployed steam generation, but numbers are hard to find and conflicting. So, the question is: Would it be more energy efficient to convert old sites and build new geothermal sites using Stirling engines?

Thanks

Bptdude (talk) 05:47, 20 November 2007 (UTC)

If there was an advantage, don't you think geothermal developers would be using Stirling engines? Reciprocating engines don't do well in large sizes (say, 5000 HP/KW and up); this is why steam turbines replace reciprocating piston steam engines for central station use over 100 years ago. --Wtshymanski (talk) 18:55, 20 November 2007 (UTC)


Oh, don't be snippy... as in "don't I think they would be doing it already?". You would be surprised what people could do, but don't. A steam locomotive is a good example of reciprocating engine being quite a succees for steam. Some were quite powerful. The question was not about one type of steam versus another type of steam engine, but about the effciency of steam engine versus Stirling engine. There are a number of Stirling discussion boards where people in developing countries are asking this very question, and want a serious answer.

Most people today don't even know what a sterling engine is. You won't find it in text books of students in American schools, I don't know about other countries. 5000 HP/KW and up.... Is there such a thing as a turbine Stirling engine? I heard of a rotary Stirling engine.

Bptdude (talk) 05:13, 21 November 2007 (UTC)

It's not covered because it's not important; it's a quirkly solution to some particular problems but the many limitations severely limit the field of application. If it was a turbine engine, it'd be a Brayton cycle - different thermodynamic cycle entirely. My old thermodynamics text book does discuss the Stirling cycle. I don't know why Stirling engines attract cult-like devotion; maybe it's easy to build table-top models? The tone of this article is far too speculative and there's too many statements that don't have references. The style has gotten really wordy. It's exhausting to read this article. Each nugget of fact is swamped by the encrustations of the current style. --Wtshymanski 16:07, 3 December 2007 (UTC)

[edit] Animated images

We now seem to have two offerings of good animated diagrams to choose from, those offered by User:Zephyris and those by User:Van helsing . Both of these are excellent pieces of graphics and it is very hard to choose one over the other. I propose that the sectional diagrams are used to explain the stages in the cycle and the perspective diagram is used to show the animation. I believe this gives the reader the greatest explanatory power, which is what should be our main criteria in building an encyclopedia. Lumos3 21:40, 11 March 2007 (UTC)

Agree, though the perspective one is currently a monster in file size, so I deleted it temporarily until I find a way to reduce the file size. The problem is that the MediaWiki software (actually ImageMagick) seems very arbitrary on if it will scale down certain animated GIFs yes or not. Purges, clear caches and patience don’t seem to help with this version. --Van helsing 09:44, 12 March 2007 (UTC)

[edit] Rhombic-Drive Beta-Stirling Image

Note the port at the top of the cylinder, which was probably intended to connect to a heater-regenerator-cooler unit, as is usually done in a SE. I admit, it is a very pretty drawing of a rhombic-drive linkage, but unfortunately the drawing does not adequately represent a SE, because it lacks heat-exchanger and a regenerator which are the most important parts of a SE. Since this drawing is missing critical engine components, it is misleading to the reader. The problem with this image, is that it serves to perpetuate the myth that a SE does not require a large surface area for heat transfer as is provided by internal heat-exchangers. For this engine to run as it is shown, without internal heat-exchangers, the requisite surface-area/volume ratio would necessitate that the cylinder bore be limited to a fraction of an inch, yet there is no indication of engine size in either the image or caption. Further to the point, the unique LTD-engine, which is usually the only type of SE that uses a displacer without a regenerator, always has a displacer that is shaped optimally as a wide flat disk. Again, this is done to maximize the surface-area to volume ratio needed for good heat transfer, and is essential to make the engine run.

This problem is made worse by the refusal of one or more editors to conceed that no regenerator is present in the image. The edit-war needs to end, and at the very least this issue needs to be resolved by explaining the omission in the caption, or better yet, the image should be replaced with an image that more accurately depicts a realistic, full-functioning SE. The SE is a "heat-engine", so it needs heat to run. Mikiemike 19:41, 13 March 2007 (UTC)

Please link to an example of the type of diagram you mean anywhere on the internet. The diagram used is consistant with others on all the web sites I have come across. The port at the top of the cylinder is probably used to replenish the working gas as it seeps past the piston seals. The diagram is also consistant with those used for internal combustion and steam engines which also dont show ancillary heat exchangers, boilers, dynamoes, batteries etc. Lumos3 22:15, 13 March 2007 (UTC)
The most important and notable feature of a SE is the heat exchangers. They are not 'ancillary', rather, they are the key to the engine. ALL of the heat flows through them. Without them, you don't really have a SE. It's a nice image, but it only shows half the engine. The ports are there to connect with the heater/regen/cooler stack. The pressure vessel seals govern the loss of working gas, not the internal seals.
The SE is NOT like an IC engine, and if you use that as the standard you're going to quickly run into a lot of confusion and misconceptions. The subject of SE's is complex enough as it is. Don't assume that every reader understands IC engines. Comparison with an IC engine should be limited to one section. One engine type per article please. Mikiemike (talk) 18:08, 24 March 2008 (UTC)--


This image looks suspiciously like something else... —Preceding unsigned comment added by Andrewlevy (talk • contribs) 03:16, 9 January 2008 (UTC)

[edit] Gamma Stirling animated image

It would be good to have an animation of the Gamma configuration in the same style as the other images. There is an example of how the gamma works here [1] . Lumos3 22:11, 27 March 2007 (UTC)

[edit] External Links, List of

This list was removed from the article by User:McNeight on June 10, 2007 , and was posted below by User:Mikiemike on June 12, 2007.

I agree that this list is verbose, and some links may be inappropriate; however, many of the links are consistent with the Wikipedia policy: Wikipedia:External links. IMHO, the list should be culled and condensed in accordance with the Wikipedia policy, and then merged back into the article, at least as references if nothing else.
Mikiemike 15:51, 12 June 2007 (UTC)

  • Agreed. Though there are some inline references that could use culling as well, doing that one at a time should be much simpler than a single person attempting to cull ~100 links based on a single interpretation of what is consistent with policy. Thanks for putting the list of links here rather than blindly restoring it to the main page. McNeight 17:23, 12 June 2007 (UTC)

[edit] External links

Wikimedia Commons has media related to:

[edit] How it works

[edit] History

[edit] Academic and technical studies

[edit] Patents

[edit] Societies and conferences

[edit] Hobbyists and enthusiasts

[edit] Commercial manufacturers and suppliers

[edit] animated gifs

Very useful, but the way they are presented right now makes them a big distraction. I'm thinking they almost need to go onto a separate page. Sadly, I dont know how to do the specific kind of edit on wikipedia, and I'm not familiar enough with the subject matter to make edits to your page, but I hope somebody can resurrect the animated gifs in a way that is less distracting. When they are right next to all the different phases I could not read the captions because my eye kept going to the animation.

Right now, I removed them so just so I can read the captions! —Preceding unsigned comment added by 207.178.4.25 (talk) 06:15, August 27, 2007 (UTC)

Just created myself an account so I'm not a random IP address... —Preceding unsigned comment added by Coryking (talk • contribs) 06:24, August 27, 2007 (UTC)

[edit] aircraft engines

I deleted this line "with altitude (internal combustion piston engines lose efficiency)" because it's not true. If anything reciprocating engines are more efficient at altitude. Someone may have gotten the wrong idea because overall the efficiency of piston powered airplanes gets worse with altitude buts that's because of the propeller. If you're talking strictly about the powerplant like I think the article should then this is inaccurate.—Preceding unsigned comment added by Arf says (talk • contribs) 07:47, 8 September 2007 (UTC)

Maybe you should discuss such things before deleting, if you are full of "if's" and "I think". You may be right about the engine versus the powerplant. I'll have to take your word for it. But, a Stirling engine may have quite different flight properties depending on the design of the engine. If designed as an air independent system, like the submarine, or something special for aircraft that might use solar for heat, similar to the NASA small remote aircraft that flys continously on solar electric cells and batteries, altitude and range might have new limits broken. Since you are an airplane expert, sorta, how high could a small aircraft fly, if the propeller engine didn't have to breath air?—Preceding unsigned comment added by Bptdude (talk • contribs) 01:15, 10 September 2007 (UTC)

I'm not trying to compare the two engines. I'm just correcting the statement that internal combustion piston engines lose efficiency. An internal combustion piston engine (aircraft or otherwise) operating at altitude will have a marginal increase in efficiency even though its total BHP will be reduced. Some fighter aircraft from world war 2 can reach 40,000 feet with supercharging. If you want to compare the efficiency versus altitude of 2 different engines then it isn't accurate to use the thrust horsepower from one versus the brake horsepower of the other.—Preceding unsigned comment added by Arf says (talk • contribs) 20:04, 10 September 2007 (UTC)

[edit] Dilbert Blog Entry

Just for interest, this page got a mention and a link on the "Dilbert Blog" by Scott Adams here . The blog post suggests that the Sterling Engine could 'save the planet'. —Preceding unsigned comment added by Bernard S. Jansen (talk • contribs) 03:37, 12 September 2007 (UTC)

Also, that it looks like a 'giant penis'. Lizard Dude 04:21, 12 September 2007 (UTC)

Kinda funny that people have been commenting on this for so long, and the comments have been removed by WikiWarriors as vandalism. Now the obvious penis appearance makes the popular culture by getting into Dilbert. In a twist of fate, as I have often failed to make people understand this concept in my own conversations, I've emailed the 'giant penis' Dilbert reference to a few earth conscience friends, who then had an epiphany about the concept. Bptdude 07:56, 12 September 2007 (UTC)

Though it is true the outline of the rhombic drive illustration does bear some resemblance to a naive 'cock and balls' drawing, I fail to see why the author of the Dilbert piece chooses to refer to it as a "giant penis", there being no scale referance. Indeed at any normally used screen resolution I would suggest it appears rather smaller than average.

the above paragraph is unsigned

dude, who cares if the illustration is accurate or not to the mentioned body parts. what is important is that it got loose in popular culture in a funny way. even more important, it helps people grasp the concept of what is capable. if you ask people about the article, often mentioned is the description of how individuals could buy specific engines and monitor them, rather than one big company owning them all. this could be huge, just becausse it would help people feel involved in saving the planet. what is insane is current political thinking about buying "carbon footprint" credits to offset buring unfiltered coal, which is the current popular thing with "green" politicians.. to put it another way, maybe even Hillary could understand the penis concept! *grins* Bptdude 06:53, 20 September 2007 (UTC)

Scott Adams may be a brilliant comedian, but AFAIK, Wikipedia is intended to be an encyclopedia, not a comedy forum. Interestingly, if your personal astuteness outweighs your perversity, and you are able to read between the lines, Mr. Adams does make some valid intellectual points that are non-sexual. IMHO, he's found his media/PR/policy/science/business niche, and he's using perverse comedy to generate hype and garner press, and then once he's won the hearts and minds, he cleverly directs that attention towards what is actually a significant and important issue of energy policy. What might surprise some readers, given the context, is that he seems to have some good points to make.

The questions that need to be answered are:

  • 1. What, if any, of this is appropriate for Wikipedia?

IMHO, some of it may be, but a lot of it isn't.

  • 2. Does posting this link conflict with Wikipedia's policy of not being a web directory?

Recall that a ton of links were removed from this page not that long ago. Do we want a whole bunch more now? Does Wikipedia really want to host a bunch of marginally off-topic links, even if it is good comedy? If what you want is comedy, why not just use a search engine to find it?

  • 3. Does the sexuality of Stirling engines have enough significance to be mentioned in the Wikipedia article?

IMHO, most likely not. And I say this not only by reason of censorship. First of all, I think that whomever would be interested in the sexual content, would probably not discover this by reading about it here, because the innuendo is intuitively obvious, and so it does not need to be spelled out. Secondly, by reason of censorship, those whom aren't interested in this trivial fun fact, have little use for this information, and they would more than likely find it offensive. Not that I necessarily think Wikipedia should be family-friendly (because a lot of it isn't), and I'm a firm believer in the first amendment. But if Wikipedia is to have any integrity, it should at least be organized and coherent. If the standard policies are not maintained, then all of Wikipedia would descend into the disheveled chaos of the internet. Frankly (excuse the pun), for starters, having a Bot that deletes the word 'penis' is a good start.

I think this issue is either too trivial to be worth a footnote in the main Stirling engine article, or else it should have it's own 18+ page, (which may or may not be part of Wikipedia, put that may be another issue).

For god's sake, I see little reason to get your sex-kicks on Wikipedia, especially on the Stirling engine page of all places. We all know there are plenty of other websites on the internet that will cater to any specific desire or mechanical fetish you may have.

  • 3. Is there any valuable content here that is non-sexual?

IMHO, there might be. Conceivably that content could be cleaned-up, and if suitable, it might be presented here. Other than that, forget it, because it's just adult sexual humor, and so at the very least, the tone is inappropriate for a general audience.

Links that are included within Wikipedia articles are intended to be for reference purposes and to pave the way for more in-depth research. If the content of the linked page is not appropriate for Wikipedia, then by proxy, the link is not appropriate either.

--Mikiemike 20:01, 2 October 2007 (UTC)

But this is about popular culture, not about it being funny or not and Wikipedia is not censored and people who are offended should have read the content disclamer and finally, if you have another replacement or any additions to the popular culture section, feel free to put it in Af648 07:03, 4 October 2007 (UTC)

I disagree. Culture is not defined by opinions expressed on one person's blog, no matter how popular the blogger/writer may be. He may influence culture, or his work may reflect culture, but that doesn't mean that everything he says is culture.

Scott Adams is a comedic writer. Which section of the newspaper is his work in? It's in the funnies. That means it is categorized as comedy. If you think differently, then the burden of proof is on you to show otherwise.

It's too bad I have to slam one of my favorite comedians, but I'm sorry, an encyclopedia is not a joke book.

Mikiemike (talk) 19:39, 5 February 2008 (UTC)--

[edit] heat sink is space itself.

The heat source is a dry solid nuclear fuel slug and the heat sink is space itself.

How does space act as a heat sink? How does a vacuum absorb heat? This sentence seems a bit fishy. 67.49.8.228 (talk) 21:38, 9 January 2008 (UTC)

In outerspace, heat transfer is by radiation, not convection.

Mikiemike (talk) 19:44, 5 February 2008 (UTC)--

[edit] Automotive Applications

I added a section discussing some history in automotive applications. I added references, but couldn't find any good reference for AMC's program since that company is now absorbed by GM. I've tried to find their old patents and failed, though I know that they had a program.

Please add or edit as necessary, but don't delete it because its an important part of automotive history and possibly an important part of future automotive developments. - Ross Moffett —Preceding unsigned comment added by 208.180.52.1 (talk) 08:01, 19 September 2007 (UTC)

[edit] Stirling Cycle

The article needs an explanation of the Stirling cycle, specifically: isothermal compression and expansion, and constant-volume heat transfer. A Stirling cycle is NOT a Carnot cycle! Someone put this in the article, and I had to take it out because it's incorrect. Mikiemike 21:44, 24 October 2006 (UTC)