Talk:Thermal efficiency

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What in blazes is going on in the thermal efficiency section? E_hp - E_r = 1 ?!?!

So E_hp was greater than one to begin with?! Something needs explanation or changing here! —The preceding unsigned comment was added by 165.124.116.206 (talk) 23:06, August 22, 2007 (UTC)

Internal combustion engines are not "thermal devices" like furnaces or steam engines. Heat is a byproduct of burning fuel to generate pressure. Heat is actually unwanted, thus radiators and so on. External combustion engines are "thermal devices" because they specifically use heat, to generate pressure. —Preceding unsigned comment added by Arantius (talk • contribs) 16:44, 3 January 2008 (UTC)

Pressure (useful work) is generated by the heating of the air inside the piston of an internal combustion engine. ...so it is a cyclic thermal device, converts heat into work and obeys the 2nd law of thermodynamics. The "unwanted heat" is due to the inherent inefficiency, as stated by the 2nd law. 86.159.124.167 (talk) 15:19, 11 January 2008 (UTC)


Contents

[edit] Applications

I undid your revision of the thermal efficiency article due to grammer and the material added being confused and out of place. I'm not sure the Carnot limit applies to Solar cells like you state (do you have any references?) and the bit about detonations just seemed odd to me. I don't think higher temperatures around shockwaves do allow higher efficiencies and while there are large temperature gradients within engines it doesn't seem relavent to the article to me. Andrew.Ainsworth (talk) 13:27, 13 January 2008 (UTC)

With a little love for the article you could have reinserted my corrections concerning the International System of Units. Grammar: I don't know, maybe you mean style? Relevant vs thinkofthechildren: Do not make the mind of our young readers dull by mentioning only the application the adults mostly look up. After all this article is classified as stub.

[edit] Solar cell thermodynamics

http://www.esqsec.unibe.ch/%5Cpub%5Cpub_152.pdf http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=APPLAB000091000006064102000001&idtype=cvips&gifs=yes http://www.amazon.com/Endoreversible-Thermodynamics-Solar-Energy-Conversion/dp/0198513925 http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/6998/18857/00870715.pdf http://trappist.elis.ugent.be/~aldevos/projects/thermo.html http://cat.inist.fr/?aModele=afficheN&cpsidt=16300686

[edit] Detonation

Pulse_detonation_engine

[edit] Internal combustion engine

http://en.wikipedia.org/wiki/Internal_combustion_engine#Engine_Efficiency

Arnero (talk) 18:07, 16 January 2008 (UTC)