Issue
EPL
Volume 83, Number 6, September 2008
Article Number 60003
Number of page(s) 6
Section General
DOI http://dx.doi.org/10.1209/0295-5075/83/60003
Published online 08 September 2008
EPL, 83 (2008) 60003
DOI: 10.1209/0295-5075/83/60003

Molecular kinetic analysis of a finite-time Carnot cycle

Y. Izumida and K. Okuda

Division of Physics, Hokkaido University - Sapporo 060-0810, Japan

izumida@statphys.sci.hokudai.ac.jp
okuda@statphys.sci.hokudai.ac.jp

received 25 February 2008; accepted in final form 25 July 2008; published September 2008
published online 8 September 2008

Abstract
We study the efficiency at the maximal power $\eta _{{\rm max}}$ of a finite-time Carnot cycle of a weakly interacting gas which we can regard as a nearly ideal gas. In several systems interacting with the hot and cold reservoirs of the temperatures $T_{{\rm h}}$ and $T_{{\rm c}}$, respectively, it is known that $\eta_\mathrm{max}=1-\sqrt{{T_\mathrm{c}}/{T_\mathrm{h}}} $, which is often called the Curzon-Ahlborn (CA) efficiency $\eta _{{\rm CA}}$. For the first time numerical experiments to verify the validity of $\eta _{{\rm CA}}$ are performed by means of molecular dynamics simulations and reveal that our $\eta _{{\rm max}}$ does not always agree with $\eta _{{\rm CA}}$, but approaches $\eta _{{\rm CA}}$ in the limit of $T_{{\rm c}}\rightarrow T_{{\rm h}}$. Our molecular kinetic analysis explains the above facts theoretically by using only elementary arithmetic.

PACS
05.70.Ln - Nonequilibrium and irreversible thermodynamics.

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