IWNET12
IWNET12
A comparative analysis of e ciency a maximum power output for some
heat engines
N. Sánchez-Salas1, R. E. González-Narváez1, M. A. Barranco-Jiménez2
1 Escuela Superior de Física y Matemáticas del IPN, México DF, México
2 Escuela Superior de Cómputo del IPN, México DF, México
Abstract
In this work, we present a comparative analysis of the e ciencies at maximum power out for dierent devices;
rst, we analyze the expressions of the e ciency at maximum power for two models of heat engines: a model
of Curzon-Ahlborn (macroscopic) and a Novikov model, in these two cases, two kinds of heat transfer laws
were considered; one, a heat transfer due to free convection described by Newton's Law of cooling and two, a
phenomenologic heat transfer comes from linear irreversible thermodynamics. On the other hand, we present
the e ciencies at maximum power for stochastic (mesoscopic) heat engines obtained by Schmiedl and Seifert
and presented in EPL 81 20003 (2008), also we compared these e ciencies with the results presented recently by
Esposito et al. published in Phys. Rev. Lett. 105, 150603 (2010). For comparing, we expanding the expressions
of e ciencies up to the third-order term of ηc, were ηc is the e ciency of Carnot (ηc = 1 − T2/T1 ). We found
some interesting similarities for the expressions of e ciencies between the macroscopic and mesoscopic models
of heat engines.
E-mail: mbarrancoj@ipn.mx