JMP  Vol.5 No.16 , October 2014
Thermodynamics and Irreversibility: From Some Paradoxes to the Efficiency of Effective Engines
Author(s) Olivier Serret*
ABSTRACT
The traditional thermodynamic theory explains the reversible phenomena quite well, except that reversible phenomena are rare or even impossible in practice. Here the purpose is to propose an explanation valid for reversible and also irreversible phenomena, irreversibility being common or realistic. It previously exposed points tricky to grasp, as the sign of the work exchange, the adiabatic expansion in vacuum (free expansion) or the transfer of heat between two bodies at the same temperature (isothermal transfer). After having slightly modified the concepts of heat transfer (each body produces heat according to its own temperature) and work (distinguishing external pressure from internal pressure), the previous points are more easily explained. At last, an engine efficiency in case of irreversible transfer is proposed. This paper is focused on the form of thermodynamics, on “explanations”; it does not question on “results” (except the irreversible free expansion of 1845...) which remain unchanged.

Cite this paper
Serret, O. (2014) Thermodynamics and Irreversibility: From Some Paradoxes to the Efficiency of Effective Engines. Journal of Modern Physics, 5, 1575-1593. doi: 10.4236/jmp.2014.516159.
References
[1]   Balian, R., CEA (2013) La longue elaboration du concept d'energie.
http://www.academie-sciences.fr/activite/hds/textes/evol_Balian1.pdf

[2]   Diu, B. (2001) Quatre questions sur la thermodynamique.
http://www.canal-u.tv/video/science_en_cours/quatre_questions_sur_la_thermodynamique_posees_a_bernard_diu.19

[3]   ENS Cachan (1987) Gaz reels dilues, 140,141.
http://www.physique.ens-cachan.fr/pagregp/enseignement/elec/corrigecompophy1987.pdf

[4]   Rowlinson, J.S. (2009) James Joule, William Thomson and the Concept of a Perfect Gas.
http://rsnr.royalsocietypublishing.org/content/64/1/43.full, extract: In 1845 Joule had tried to verify this assumption, which Thomson always called “Mayer’s hypothesis”, by expanding a cylinder of compressed gas into an empty cylinder but, as he later admitted, he failed because the heat capacity of his vessels was too large compared with that of the gas. We now know that for air at atmospheric pressure and temperature the difference between the two terms on the right of this equation is only about 3 parts per thousand of either of them.

[5]   (1976) Detente, Larousse,
http://www.larousse.fr/archives/grande-encyclopedie/page/4197 extract: The question arose whether the expansion of a gas in a vacuum, that is to say without external work, involving a change in temperature of the gas, assumed thermally insulated (expansion to constant internal energy); LJ Gay-Lussac then JP Joule have concluded in the negative, but their experiences were not very precise; GA Hirn (1865) brought to light a slight cooling.

[6]   Dr. P. Puzo from Institut National de Physique Nucleaire (2012) Description des fluides reels, 127.
https://users.lal.in2p3.fr/puzo/thermo/ch6_thermo.pdf

[7]   Joule Expansion, Wikipedia.
http://en.wikipedia.org/wiki/Joule_expansion

[8]   (2009) Gas Expansion Temperature Drop.
http://www.oilngasseparator.info/gas-production-facility/hydrates/gas-
expansion-temperature-drop.html


[9]   Rapin, P., Jacquard, P. and Desmons, J. (2011) Technologie des Installations Frigorifiques, Edition Dunod, 492. Extract: The obtained cooling [of air] is in the order of 0.25°C for a pressure drop of 1 bar.

[10]   Queyrel, J.-L. and Mesplede, J. (1996) Precis de Physique No. 6: Thermodynamique Prepas, Edition Breal, 149.

[11]   Trizac, E. (1999) Cours de Thermodynamique.
http://www.lptms.u-psud.fr/membres/trizac/Ens/Livre_thermo.pdf

[12]   Internal Energy, Wikipedia.
http://en.wikipedia.org/wiki/Internal_energy

[13]   Perez, J.-P. (2001) Detente de Joule et Gay-Lussac d’un gaz de Clausius.
http://culturediff.pagesperso-orange.fr/jpp/ouvrage6/Thermo09-07.pdf

[14]   Serres, M. and Farouki, N. (1997) Le Tresor-Dictionnaire des Sciences. Flammarion, 855.

[15]   Gicquel, R., Mines de Paris Tech, Cycle de Carnot, p.4/9.
http://direns.mines-paristech.fr/Sites/Thopt/fr/co/bases-thermodynamique.html

[16]   Taillet, R., Universite de Savoie (2012) Cours de thermodynamique.
http://podcast.grenet.fr/episode/cours-7-2/

 
 
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