|
[[Image:GasTurbine.jpg|thumb|right|400px|This machine has a single-stage radial [[compressor]] and turbine, a [[recuperator]], and [[foil bearings]]. ]]
'''This is part of [[Wikipedia:Criteria_for_speedy_deletion/Proposal]].'''
A '''gas turbine''' is a rotary [[engine]] that extracts energy from a flow of [[combustion]] gas. It has an upstream [[compressor]] coupled to a downstream [[turbine]], and a combustion chamber in-between. ('''Gas turbine''' may also refer to just the [[turbine]] element.)
==7 (RPG characters)==
:'''any article that states that it describes a character (but not a race, or type of creature) from any roleplaying game (including [[MUD]]s and [[MMORPG]]s), that is not also a real or fictional person outside that roleplaying game''' should be added to the criteria for speedy deletion.
*Perhaps surprisingly, people frequently write characters about their character from [[Everquest]] or [[Dungeons & Dragons]]. Whenever found on VFD, these articles get unanimous votes to delete, possibly excepting a vote by the article's creator.
*Quite simply, no matter how high-level, how powerful or how well-equipped, a character from a roleplaying game is not encyclopedic.
*Characters from popular fiction, such as [[Elminster]] or [[Pug]], are covered by the exception since they appear in written books. This also serves to exclude people who use [[Buffy]] or any existing person as their role-playing alter-ego.
*If you are unsure about this proposal, consider that there is a proposed [[Wikipedia:Criteria for speedy deletion/Proposal/Test run|test run]] to try it out for a month.
[[Energy]] is added to the gas stream in the [[combustor]], where [[air]] is mixed with [[fuel]] and [[ignition system|ignited]]. Combustion increases the [[temperature]], [[velocity]] and [[volume]] of the gas flow. This is directed through a diffuser ([[nozzle]]) over the turbine's blades, spinning the turbine and powering the compressor.
'''[{{SERVER}}{{localurl:{{NAMESPACE}}:{{PAGENAME}}|action=edit&section=2}} vote] – [[{{NAMESPACE}} talk:{{PAGENAME}}|discuss]]'''
Energy is extracted in the form of shaft power, compressed air and thrust, in any combination, and used to power [[aircraft]], [[train]]s, [[ship]]s,[[generator]]s, and even [[tank]]s.
==Votes==
===Support===
#<font color=#00A86B>[[User:Android79|<small>A</small>и<small>D</small>я<small>01D</small>]]</font><font color=#B87333>[[User talk:Android79|<small>TALK</small>]]</font><font color=#0047AB>[[Special:Emailuser/Android79|<small>EMAIL</small>]]</font> July 4, 2005 15:51 (UTC)
#pretty obvious IMO. [[User:DESiegel|DES]] 4 July 2005 18:43 (UTC)
#Ditto. --[[User:A D Monroe III|A D Monroe III]] 4 July 2005 19:39 (UTC)
#Leave a note that only admins familiar with the claimed fictional setting should perform the speedy. '''[[User:Humblefool|humble]]'''[[User talk:Humblefool|fool]][[Special:Randompage|®]] 4 July 2005 21:03 (UTC)
#--[[User:Henrygb|Henrygb]] 4 July 2005 21:39 (UTC)
#[[User:Petaholmes|nixie]] 4 July 2005 23:47 (UTC)
#A good start to getting some of that fancruft off of the site... support. --[[User:Idont havaname|Idont Havaname]] 5 July 2005 00:08 (UTC)
#[[User:NatusRoma|NatusRoma]] 5 July 2005 00:46 (UTC)
#An easy Google search will establish whether the person also exists outside the game, and the article ''has'' to ''state'' that it is a character or it must go to VfD. If they 'forget' to ''state'' that, they get to have their day in VfD. -[[User:Splash|Splash]] 5 July 2005 01:02 (UTC)
#:The article also has to state that it is not a real or fictional thing outside of the game, correct? [[User:Factitious|Factitious]] July 6, 2005 01:57 (UTC)
#Support - certainly, at least, to the extent that we have articles which state that "Darth Foo" is Chuck Foo's character that he plays in his MMPORG. --[[User:BDAbramson|<font style="background: lightgreen"> BDAbramson</font>]] [[User talk:BDAbramson|<sup><b>talk</b></sup>]] July 5, 2005 02:08 (UTC)
#VfD will still be needed to sort out some of these, but at least we have a tool to deal with the worst offenders. [[User:Denni|Denni]][[User_talk:Denni|<font color=#228822>☯</font>]] 2005 July 5 02:36 (UTC)
#[[user:mikkalai|mikka]] [[user talk:mikkalai|(t)]] 5 July 2005 03:07 (UTC)
#— '''[[User:Philwelch|Phil]]''' ''[[User_talk:Philwelch|Welch]]'' 5 July 2005 03:20 (UTC)
#[[User:Gadfium|gadfium]] 5 July 2005 03:25 (UTC)
#[[User:Fuzheado|Fuzheado]] | [[User talk:Fuzheado|Talk]] 5 July 2005 03:48 (UTC)
#[[User:Cryptic|Cryptic]] [[User talk:Cryptic|(talk)]] 5 July 2005 04:08 (UTC)
#[[User:Harro5|Harro5]] July 5, 2005 05:49 (UTC)
#Support. [[User:FCYTravis|FCYTravis]] 5 July 2005 06:56 (UTC)
#[[User:Grutter|G Rutter]] 5 July 2005 08:57 (UTC)
#[[User:JoJan|JoJan]] 5 July 2005 08:59 (UTC)
#If it is not obvious from the article that the topic has wider significance then it is worse than a stub because it is misleading. — [[User:TheoClarke|Theo ]] [[User_talk:TheoClarke|(Talk)]] 5 July 2005 10:43 (UTC)
# '''Support.''' -- [[User:Schneelocke|Schnee]] (''[[User talk:Schneelocke|cheeks clone]]'') 5 July 2005 12:27 (UTC)
# '''Support.''' --[[User:Scimitar|Scimitar]] 5 July 2005 23:28 (UTC)
#'''Support'''. Extremely crufty. [[User:Jayjg|Jayjg ]]<sup><font color="DarkGreen">[[User_talk:Jayjg|(talk)]]</font></sup> 6 July 2005 02:29 (UTC)
#'''support'''. and obvious CSD. [[User:Sasquatch|Sasquatch{{unicode|′}}]]{{unicode|↔}}[[User_talk:Sasquatch|Talk]]{{unicode|↔}}[[Special:Contributions/Sasquatch|Contributions]] July 6, 2005 04:33 (UTC)
#'''Support'''. -[[User:R. S. Shaw|R. S. Shaw]] 6 July 2005 05:03 (UTC)
#'''Support'''. I imagine they mostly get speedied as nonsense anyway. --[[User:Mel Etitis|Mel Etitis]] ([[User talk:Mel Etitis|<font color="green">Μελ Ετητης</font>)]] 6 July 2005 09:23 (UTC)
#— [[User:Trilobite|Trilobite]] ([[User_talk:Trilobite|Talk]]) 6 July 2005 10:47 (UTC)
#--[[User:Porturology|Porturology]] 6 July 2005 13:08 (UTC)
# [[User:The Epopt|➥the Epopt]] 6 July 2005 13:42 (UTC)
#--[[User:Aphaia|<font color=midnightblue>Aphaea</font>]][[User talk:Aphaia|<font small color=gold>*</font>]] 6 July 2005 14:54 (UTC)
# Yup. [[User:Lubaf|Thanks]], <br>[[User_talk:Lubaf|Luc "Somethingorother" French]] 6 July 2005 20:29 (UTC)
#[[User:Carnildo|Carnildo]] 6 July 2005 22:07 (UTC)
#[[User:Jpgordon|jpgordon]][[User talk:Jpgordon|∇∆∇∆]] 7 July 2005 02:42 (UTC)
# '''Support'''. <font color="red">[[User:Ral315|ral]]</font><font color="green">[[User talk:Ral315|315]]</font> July 7, 2005 05:28 (UTC)
# -- [[User:Ricky81682|Ricky81682]] ([[User talk:Ricky81682|talk]]) July 7, 2005 08:20 (UTC)
# Zandor, from the village in the west, '''supports''' this proposal, for a bag of rubies. [[User:Who|<font color=#FF0033><></font>Who]][[User talk:Who|<font color=#00Ff00>?</font><font color=#FF00FF>¿</font><font color=#0033FF>?</font>]] 7 July 2005 16:35 (UTC)
#'''Strong Support''' [[User:Thames|<nowiki></nowiki>]]—[[User:Thames|thames]] 7 July 2005 20:51 (UTC)
#'''weak support''' [[User:Drini|drini]] [[User Talk:Drini|☎]] 7 July 2005 20:57 (UTC)
# '''Support''' - [[User:Texture|<font color=red>Tεx</font>]][[User Talk:Texture|<font color=blue>τ</font>]][[User:Texture|<font color=red>urε</font><!-- TANSTAAFL -->]] 7 July 2005 21:27 (UTC)
#'''Weak support'''. This is a very specialized set of useless articles and I doubt many admins are going to have this criteria in mind when doing new article patrol, but I don't believe it's dangerous. [[User:Dbiv|David]] [[Image:Arms-westminster-lb.jpg|25px]] | [[User talk:Dbiv|Talk]] 7 July 2005 22:32 (UTC)
#'''Support''', RPG characters are vanity ''and'' fan-fiction. [[User:Gazpacho|Gazpacho]] 8 July 2005 02:51 (UTC)
#'''Support'''. A no brainer. [[User:Kaibabsquirrel|Kaibabsquirrel]] 8 July 2005 07:59 (UTC)
#[[User:Merovingian|<font color="FF0000">M</font><font color="CC9900">e</font><font color="FF9933">r</font><font color="FFFF00">o</font><font color="CCFF33">v</font><font color="66FF33">i</font><font color="00CC99">n</font><font color="3399FF">g</font><font color="0000FF">i</font><font color="330066">a</font><font color="330033">n</font>]] [[User talk:Merovingian|(t)]] [[Special:Contributions/Merovingian|(c)]] July 8, 2005 09:19 (UTC)
#'''Support''', fancruft must die [[User:Proto|Proto]]<small> [[User_talk:Proto|t]] [[Special:Contributions/Proto|c]]</small> 8 July 2005 10:50 (UTC)
#'''Support'''. [[Drizzt]] is encyclopedic, my own DnD character is not, and wouldn't be even if I played well. July 9, 2005 04:37 (UTC)
#'''Support''' [[User:Gwk|Gwk]] 9 July 2005 16:39 (UTC)
#'''Support'''. [[User:TheCoffee|TheCoffee]] 21:27, 9 July 2005 (UTC)
#'''Support.''' Delete first, ask questions later. [[User:Karmosin|Peter]] <sup>[[User talk:Karmosin|Isotalo]]</sup> 17:28, 10 July 2005 (UTC)
#'''Support'''. Certainly. --[[User:Canderson7|Canderson]]'''[[User_talk:Canderson7|7]]''' 18:36, July 10, 2005 (UTC)
<br style="clear: right"/>
===Oppose===
#<s>Too ambiguous. [[Modron (Dungeons & Dragons)]] could be considered eligible by editors unfamiliar with RPGs, as they appear to be ''characters from a roleplaying game, that are not also real or fictional people outside that roleplaying game.'' [[User:Pburka|Pburka]] 4 July 2005 16:58 (UTC)</s>
==Theory of operation==
#*They clearly come under the "Race or type of creature" exception. [[User:DESiegel|DES]] 4 July 2005 18:42 (UTC)
Gas turbines are described [[thermodynamics|thermodynamically]] by the [[Brayton cycle]], in which air is compressed [[isentropic]]ally, [[combustion]] occurs at constant pressure, and expansion over the turbine occurs isentropically back to the starting pressure.
#**That was added after I voted. <s>I will abstain for now until I do a bit of research to find out how often this could be applied.</s> [[User:Pburka|Pburka]] 4 July 2005 23:38 (UTC)
#***I continue to '''oppose'''. Since [[Wikipedia:Votes for deletion/Log/2005 June 30]] I can only find one VfD which might have qualified under this criteria: [[Mechasaurus]]. [[User:Pburka|Pburka]] 5 July 2005 01:41 (UTC)
In practise, friction and turbulence cause:
# I object primarily because the wording of this item was [http://en.wikipedia.org/w/index.php?title=Wikipedia:Criteria_for_speedy_deletion/Proposal&diff=next&oldid=18127034 added] by [[User:Radiant!]] without discussion prior to this vote being opened. -- [[User:Netoholic|Netoholic]] [[User talk:Netoholic|@]] 4 July 2005 19:05 (UTC)
# ''a character (but not a race, or type of creature) <nowiki>[...]</nowiki> that is not also a real or fictional person outside that roleplaying game'' — As with [[Wikipedia:Criteria for speedy deletion/Proposal/6|proposal 6]], proving a negative is too large a task for just 2 editors to perform. [[User:Uncle G|Uncle G]] 4 July 2005 21:11 (UTC)
a) non-isentropic compression - for a given overall pressure ratio, the compressor delivery temperature is higher than ideal
#*While I agree with Uncle G's remark on proposal six, I don't think it applies here. It is obvious from an RPG article whether it concerns a character (e.g. [[Raistlin]], [[Cyric]]) or a type of creature (e.g. [[Beholder]], [[Drow]]). Also note that many of the latter are also part of existing mythologies. [[User:Radiant!|R]][[User_talk:Radiant!|adiant]][[meta:mergist|_<font color="orange">>|<</font>]] July 5, 2005 08:43 (UTC)
#**...but it is ''not'' obvious whether a character, race, or type of creature is "not also a real or fictional person outside that roleplaying game". [[User:Uncle G|Uncle G]] 5 July 2005 10:11 (UTC)
b) non-isentropic expansion - although the turbine temperature drop necessary to drive the compressor is unaffected, the associated pressure ratio is greater, which decreases the expansion available to provide useful work.
#As with Proposal 6. Uncle G is right on the money there and here. [[User:Blankfaze|{{User:Blankfaze/sig}}]] 5 July 2005 03:50 (UTC)
# Per Uncle G. [[User:Xoloz|Xoloz]] 5 July 2005 06:44 (UTC)
a) a pressure loss in the combustor - reduces the expansion available to provide useful work.
#These are merge candidates, probably wouldn't even pass in VfD. See also [[Wikipedia:Criteria for speedy deletion/Proposal/Z]] --[[User:Tony Sidaway|Tony Sidaway]]|[[User talk:Tony Sidaway|Talk]] 5 July 2005 15:14 (UTC)
#Merge/VfD these — '''[[User:Bcat|Bcat]]''' ([[User talk:Bcat|talk]] | [[Special:Emailuser/Bcat|email]]) 5 July 2005 15:49 (UTC)
#As per Uncle G. Consider [[Drizzt]] (sp?). [[User:Meelar|Meelar]] [[User talk:Meelar|(talk)]] July 5, 2005 16:49 (UTC)
[[Image:Brayton cycle.png]]
#*Drizzt is a character from several novels, as plainly stated in the article. [[User:Radiant!|R]][[User_talk:Radiant!|adiant]][[meta:mergist|_<font color="orange">>|<</font>]] July 5, 2005 21:12 (UTC)
#Objecting on the grounds that this is absurdly specific. These are hardly ever on VfD and the idea of specifically having this as a clause for speedy deletion is bureaucracy and instruction creep gone mad. ''Maybe'' this should be an example in a well-worded "unverifiable trash" clause, but in reality this sort of thing often requires ''speedy action'' (where action includes merge and redirection as well as deletion) rather just speedy delete. [[User:Pcb21|Pcb21|]] [[User_talk:Pcb21|Pete]] 5 July 2005 17:06 (UTC)
As with all cyclic [[heat engine]]s, higher combustion temperature means greater [[efficiency]]. The limiting factor is the ability of the steel, ceramic, or other materials that make up the engine to withstand heat and pressure. Considerable engineering goes into keeping the turbine parts cool. Most turbines also try to recover exhaust heat, which otherwise is wasted energy. [[Recuperator]]s are [[heat exchanger]]s that pass exhaust heat to the compressed air, prior to combustion. [[Combined cycle]] designs pass waste heat to [[steam turbine]] systems. And [[combined heat and power]] (co-generation) uses waste heat for hot water production.
#Poor wording. Something notable could fall through the cracks on this one. [[User:Acegikmo1|Acegikmo1]] 5 July 2005 19:20 (UTC)
#*Please provide an example? [[User:Radiant!|R]][[User_talk:Radiant!|adiant]][[meta:mergist|_<font color="orange">>|<</font>]] July 5, 2005 21:12 (UTC)
Mechanically, gas turbines can be considerably less complex than [[internal combustion]] piston engines. Simple turbines might have one moving part: the shaft/compressor/turbine/alternator-rotor assembly (see image above), not counting the fuel system.
#VFD, not CSD - [[User:David Gerard|David Gerard]] 5 July 2005 21:49 (UTC)
# '''Oppose'''. Overly complicated rules which involve proving negatives don't belong on CSD. [[User:Factitious|Factitious]] July 6, 2005 00:09 (UTC)
More sophisticated turbines may have multiple shafts (spools), hundreds of turbine blades, movable stator blades, and a vast system of complex piping, combustors and heat exchangers.
#--[[User:Mononoke|Mononoke]] 6 July 2005 00:30 (UTC)
# '''Oppose'''. Some pages like these really shouldn't come up for any sort of deletion, they should be merged/redirected. [[User:Christopherparham|Christopher Parham]] [[User_talk:Christopherparham|(talk)]] 2005 July 6 05:02 (UTC)
As a general rule, the smaller the engine the faster the shaft/s rotate, to maintain tip speed: [[Jet engine]]s operate around 10,000 rpm and micro turbines around 100,000 rpm.
#'''Oppose''' per Uncle G, plus attempts to add a bizarre level of instruction creep to establish specific 'Speedy' criteria for something that comes along so infrequently. [[User:Unfocused|<FONT COLOR="#006699">Un</FONT>]][[User talk:Unfocused|focused]] 6 July 2005 07:50 (UTC)
#'''Oppose''' These are already pretty obvious CSDs. [[User:Stewartadcock|Stewart Adcock]] 6 July 2005 08:43 (UTC)
[[Thrust bearing]]s and [[plain bearing|journal bearings]] are a critical part of design. Traditionally, they have been [[Fluid_bearing|hydrodynamic oil bearings]], or oil-cooled [[Ball_bearing|ball bearings]]. This is giving way to hydrodynamic [[foil bearing]]s, which have become common place in micro turbines and APU’s (auxiliary power units.)
#*Under what criterion? "Common sense" is not a speedy criterion. [[User:Gwalla|<nowiki></nowiki>]] — [[User:Gwalla|Gwalla]] | [[User talk:Gwalla|Talk]] 7 July 2005 19:14 (UTC)
#'''Oppose''' per Uncle G, and because this is getting too specific. [[User:Sietse Snel|Sietse]] 6 July 2005 10:42 (UTC)
==[[Jet engine]]s==
#'''Oppose''', instruction creep unnecessary given rarity. [[User:Jdforrester|James F.]] [[User_talk:Jdforrester|(talk)]] 6 July 2005 14:24 (UTC)
See [[jet engine]] page.
#'''Oppose'''. Instruction creep. <s> and I agree with Mel Etitis that most of this stuff gets deleted as nonsense, and therefore this proposal isn't necessary.</s> --[[User:Deathphoenix|Death]][[User_talk:Deathphoenix|'''phoenix''']] 6 July 2005 14:59 (UTC) Whether such articles are on literary characters or RPG characters is beyond the scope of a speed-deleting admin. It takes a VfD to determine that. --[[User:Deathphoenix|Death]][[User_talk:Deathphoenix|'''phoenix''']] 7 July 2005 18:43 (UTC)
#*Except that [[Wikipedia:patent nonsense]] is defined as being completely meaningless or unsalvageably incoherent: things like "gdfgfdl" or "mind hell loves chunky frog". Articles on RPG player characters are usually understandable (or else they wouldn't be identified as such). So, while these do get speedied as nonsense, it's actually against the rules to do so. [[User:Gwalla|<nowiki></nowiki>]] — [[User:Gwalla|Gwalla]] | [[User talk:Gwalla|Talk]] 6 July 2005 19:12 (UTC)
== Gas turbines for electrical power production ==
#**Good point. Once we get beyond that, however, it takes a VfD to determine whether a character is from an RPG or not. I've changed the comments in my vote to reflect that. --[[User:Deathphoenix|Death]][[User_talk:Deathphoenix|'''phoenix''']] 7 July 2005 18:43 (UTC)
[[Image:GE_H_series_Gas_Turbine.jpg|thumb|left|350px| GE H series power generation gas turbine. This 400-[[megawatt]] unit has a rated [[Thermodynamic_efficiency|thermal efficiency]] of 60% in [[combined cycle]] configurations.]]
#***Not necessarily; see [[Cachero]]—that article states right out that it's somebody's character. [[User:Gwalla|<nowiki></nowiki>]] — [[User:Gwalla|Gwalla]] | [[User talk:Gwalla|Talk]] 7 July 2005 19:14 (UTC)
#Complication. --[[User:ArmadniGeneral|ArmadniGeneral]] 6 July 2005 16:14 (UTC)
Industrial gas turbines range in size from truck-mounted mobile plants to enormous, complex systems.
#'''Oppose'''. This is redundant with the vanity policy. --[[User:Fubar Obfusco|FOo]] 6 July 2005 16:33 (UTC)
#*Vanity is not a speedy criterion. [[User:Gwalla|<nowiki></nowiki>]] — [[User:Gwalla|Gwalla]] | [[User talk:Gwalla|Talk]] 6 July 2005 19:12 (UTC)
The power turbines in the largest industrial gas turbines operate at 3,000 or 3,600 [[rpm]] to match the [[alternating current|AC]] [[power grid]] frequency and to avoid the need for a reduction gearbox. Such engines require a dedicated building.
# terrible wording! No idea what would or would not qualify. [[User:Kaldari|Kaldari]] 6 July 2005 20:19 (UTC)
# '''Oppose'''. As written, it seems to me that an arguement could be made that it applies to the recently Featured Article, [[Link (Legend of Zelda)]], as many people referr to the Zelda series as being a roleplaying game (though debated). [[User:Fieari|Fieari]] July 6, 2005 21:45 (UTC)
They can be particularly efficient—up to 60 percent—when waste heat from the gas turbine is recovered by a conventional steam turbine in a [[combined cycle]] configuration.
#*It certainly could apply to that. There is nothing in the proposal to ensure that it will only apply to non-notable examples. [[User:Factitious|Factitious]] July 7, 2005 10:35 (UTC)
#*'''Oppose''' I don't see why a special exemption should be made for fictional characters from novels over fictional characters from RPGs. [[User:Axon|Axon]] 7 July 2005 14:34 (UTC)
Simple cycle gas turbines in the power industry require smaller capital investment than combined cycle gas, [[coal]] or [[nuclear]] plants and can be designed to generate small or large amounts of power. Also, the actual construction process can take as little as several weeks to a few months, compared to years for baseload plants. Their other main advantage is the ability to be turned on and off within minutes, supplying power during peak demand. Large simple cycle gas turbines may produce several hundred megawatts of power and approach 40 percent [[Thermodynamic_efficiency|thermal efficiency]].
#**Because role playing runs are ephemeral, and published novels are not. [[User:Gwalla|<nowiki></nowiki>]] — [[User:Gwalla|Gwalla]] | [[User talk:Gwalla|Talk]] 7 July 2005 19:14 (UTC)
<br style="clear: left"/>
#'''Oppose''' Arbitrary and bizarre discrimination. [[User:Nohat|Nohat]] 7 July 2005 16:14 (UTC)
#'''Oppose''', this seems as arbitrary as to say that you can't have articles on individual movie or tv show characters. Wouldn't this involve the speedy deletion of all articles under [[:Category:Final Fantasy characters]]? Boo. --[[User:DropDeadGorgias|DropDeadGorgias]] [[User_talk:DropDeadGorgias|(talk)]] July 7, 2005 17:10 (UTC)
==Micro turbines==
#'''Oppose'''. Why RPGs are singled out here? This should go through normal VfD. -- [[User:Rune.welsh|Rune Welsh]] [[User_talk:Rune.welsh|ταλκ]] July 8, 2005 09:17 (UTC)
[[Image:Micro turbine.jpg|thumb|right|200px|A micro turbine designed for [[DARPA]] by M-Dot]]
#[[User:24ip|24]] at 9 July 2005 18:34 (UTC)
# '''Oppose''' as phrased. The proponents clearly intend that [[Drizzt Do'Urden]] and other published NPC's should not come under this rule; but that's '''not what it says'''. [[User:Pmanderson|Septentrionalis]] 21:31, 10 July 2005 (UTC)
Also known as:
*Turbo alternators
*Gensets
*MicroTurbine® (registered trademark of [[Capstone Turbine Corporation]])
*Turbogenerator® (registered tradename of [[Honeywell Power Systems]], Inc.)
'''Micro turbines''' are becoming wide spread for [[Distributed generation|distributed power]] and [[cogeneration|combined heat and power]] applications. They range from handheld units producing less than a [[kilowatt]] to commercial sized systems that produce tens or hundreds of kilowatts.
Part of their success is due to advances in electronics, which allow unattended operation and interfacing with the commercial power grid. Electronic power switching technology eliminates the need for the generator to be synchronized with the power grid. This allows, for example, the generator to be integrated with the turbine shaft, and to double as the starter motor.
Micro turbine systems have many advantages over piston engine generators, such as higher power density (with respect to footprint and weight), extremely low emissions and few, or just one, moving part. Those designed with [[foil bearings]] and air-cooling operate without oil, coolants or other hazardous materials. However, piston engine generators are quicker to respond to changes in output power requirement.
They accept most commercial fuels, such as [[natural gas]], [[propane]], [[diesel]] and [[kerosene]]. The are also able to produce [[renewable energy]] when fueled with [[biogas]] from [[landfills]] and [[sewage treatment]] plants.
Micro turbine designs usually consist of a single stage radial compressor, a single stage [[radial turbine]] and a recuperator. Recuperators are difficult to design and manufacture because they operate under high pressure and temperature differentials. Exhaust heat can be used for water heating, drying processes or absorption chillers, which create cold for air conditioning from heat energy instead of electric energy.
Typical micro turbine efficiencies are 25 to 35 percent. When in a combined heat and power [[cogeneration]] system, efficiencies of greater than 80 percent are commonly achieved.
==Auxiliary power units==
[[Auxiliary power unit]]s (APUs) are small gas turbines designed for auxiliary power of larger machines, usually [[aircraft]]. They are well suited for supplying compressed air for aircraft ventilation (with an appropriate compressor design), start-up power for larger [[jet engine]]s, and electrical and hydraulic power. (These are not to be confused with the auxiliary propulsion units, also abbreviated APUs, aboard the gas-turbine-powered Oliver Hazard Perry-class guided-missile frigates. The Perrys' APUs are large electric motors that provide maneuvering help in close waters, or emergency backup if the gas turbines are not working.)
==Gas turbines in vehicles==
Gas turbines are used on [[ship]]s, [[locomotive]]s, [[helicopter]]s, and in [[tank]]s. A number of experiments have been conducted with gas turbine powered [[automobile]]s.
In 1950, designer F. R. Bell and Chief Engineer Maurice Wilks from British car manufacturers [[Rover (car)|Rover]] unveiled the first car powered with a gas turbine engine. The two-seater JET1 had the engine positioned behind the seats, air intake grilles on either side of the car and exhaust outlets on the top of the tail. During tests, the car reached top speeds of 140 km/h, at a turbine speed of 50,000 rpm. The car ran on [[petrol]], [[paraffin]] or [[diesel]] oil, but fuel consumption problems proved insurmountable for a production car. It is currently on display at the London [[Science Museum (London)|Science Museum]]. Rover and the BRM [[Formula One]] team joined forces to produce a gas turbine powered coupe, which entered the 1963 [[24 hours of Le Mans]], driven by [[Graham Hill]] and Richie Ginther. It averaged 107.8 mph (173 km) and had a top speed of 142 mph (229 km/h). American car manufacturer [[Chrysler]] demonstrated several prototype gas turbine-powered cars from the early 1950s through the early 1980s. [http://www.aardvark.co.nz/pjet/chrysler.shtml A history of Chrysler turbine cars]. In [[1993]] [[General Motors]] introduced the first commercial gas turbine powered [[hybrid vehicle]]—as a limited production run of the [[EV-1]]. A [[Williams International]] 40 kW turbine drove an alternator which powered the battery-electric powertrain. The turbine design included a [[recuperator]].
Gas turbines offer a high-powered engine in a very small and light package. However, they are not as responsive and efficient as small piston engines over the wide range of rpms and powers needed in vehicle applications. Also, turbines have historically been more expensive to produce than piston engines, though this is partly because piston engines have been mass-produced in huge quantities for decades, while small turbines are rarities. It is also worth noting that a key advantage of jets and [[turboprop]]s for aeroplane propulsion - their superior performance at high altitude compared to piston engines, particularly [[natural aspiration|naturally-aspirated]] ones - is irrelevant in automobile applications. Their power-to-weight advantage is far less important. Their use in hybrids reduces the second problem. Capstone currently lists on their website a version of their turbines designed for installation in hybrid vehicles.
Production gas turbine motorcycle first appeared in [[MTT Turbine SUPERBIKE]] in 2000. This high-priced machine is produced in miniscule numbers.
Use of gas turbines in military tanks has been more successful. In the 1950s, a [[Conqueror tank | Conqueror heavy tank]] was experimentally fitted with a [[Parsons]] 650-hp gas turbine, and they have been used as [[auxiliary power unit]]s in several other production models. Today, the Soviet/Russian [[T-80]] and U.S. [[M1 Abrams]] tanks use gas turbine engines. See [[Tank#Gas turbines |tank]] for more details.
===Naval use===
Gas turbines are used in many naval vessels, where they are valued for their high power-to-weight ratio and their ships' resulting acceleration and ability to get underway quickly. The first gas-turbine-powered naval vessel was the [[Royal Navy]]'s Motor Gun Boat ''MGB 2009'' (formerly ''MGB 509'') converted in 1947. The first large, gas-turbine powered ships, were the Royal Navy's [[Tribal class frigate|Type 81 (Tribal class)]] [[frigate]]s, the first of which ([[HMS Ashanti (F117)|HMS ''Ashanti'']]) was commissioned in [[1961]].
The first U.S. gas-turbine powered ships were the [[United States Coast Guard|U.S. Coast Guard]]'s [[Hamilton class cutter|''Hamilton''-class]] [[USCG high endurance cutter|High Endurance Cutters]] the first of which ([[USCGC Hamilton (WHEC-715)|USCGC ''Hamilton'']]) commissioned in [[1967]]. Since then, they have powered the [[United States Navy|U.S. Navy]]'s [[Oliver Hazard Perry class frigate|''Perry''-class frigates]], [[Spruance class destroyer|''Spruance''-class]] and [[Arleigh Burke class destroyer|''Arleigh Burke''-class]] [[destroyer]]s, and [[Ticonderoga class cruiser|''Ticonderoga''-class guided missile cruisers]]. [[USS Makin Island (LHD-8)|USS ''Makin Island'']], a modified [[Wasp class amphibious assault ship|''Wasp''-class amphibious assault ship]], is to be the Navy's first [[amphibious assault ship|amphib]] powered by gas turbines.
==Amateur gas turbines==
A popular hobby is to construct a gas turbine from an automotive [[turbocharger]]. A combustion chamber is fabricated and plumbed between the compressor and turbine. Like many technology based hobbies, they tend to give rise to manufacturing businesses over time. Several small companies manufacture small turbines and parts for the amature. See external links for resources.
==Advances in technology==
Gas turbine technology has steadily advanced since its inception and continues to evolve; research is active in producing ever smaller gas turbines. Computer design, specifically [[CFD]] and [[finite element analysis]] along with material advances, has allowed higher compression ratios and temperatures, more efficient combustion, better cooling of engine parts and reduced emissions. Additionally, compliant [[foil bearing]]s were commercially introduced to gas turbines in the [[1990s]]. They can withstand over a hundred thousand start/stop cycles and eliminated the need for an oil system.
On another front, microelectronics and power switching technology have enabled commercially viable micro turbines for distributed and vehicle power. An excellent example is the Capstone line of micro turbines, which do not require an oil system and can run unattended for months on end.
==See also==
*[[turbine]]
*[[jet engine]]
*[[Brayton cycle]]
==Further reading==
* ''Gas Turbine Engines for Model Aircraft'' by [[Kurt Schreckling]], ISBN 0 9510589 1 6 Traplet Publications
==External links==
* [http://web.mit.edu/aeroastro/www/labs/GTL/gtl_about.html MIT Gas Turbine Laboratory]
* [http://www.memagazine.org/backissues/october97/features/turbdime/turbdime.html MIT Microturbine research]
* [http://www.sciencemuseum.org.uk/collections/treasures/margas.asp First Marine Gas Turbine 1947]
'''Amature groups and small manufacturers'''
* [http://groups.yahoo.com/group/DIYGasTurbines DIY Gas Turbines Yahoo Group]
* [http://www.power.alstom.com/home/equipment___systems/turbines/gas_turbines/7323.EN.php?languageId=EN&dir=/home/equipment___systems/turbines/gas_turbines/ ALSTOM Gas Turbines]
* [http://www.nyethermodynamics.com Nye Thermodynamics Corporation]
* [http://www.Innodyn.com Innodyn]
* [http://www.m-dot.com/page8.html M-Dot Microturbines]
'''Large turbine manufacturers'''
* [http://www.rolls-royce.com/energy/products/oilgas/gasturb.jsp Rolls-Royce Gas Turbines]
* [http://www.mpshq.com/products_gasturbines.htm Mitsubishi Gas Turbines]
* [http://www.gepower.com/prod_serv/products/gas_turbines_cc/en/index.htm GE Gas Turbines]
* [http://www.siemenswestinghouse.com/en/gasturbinesitem/index.cfm Siemens Gas Turbines]
* [http://www.microturbine.com/ Capstone Microturbines]
* [http://mysolar.cat.com/cda/layout Solar Turbines]
[[Category:Engines]]
[[Category:Turbines]]
[[Category:Gas turbines]]
[[Category:Marine propulsion]]
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