Issue
EPL
Volume 81, Number 2, January 2008
Article Number 20003
Number of page(s) 6
Section General
DOI http://dx.doi.org/10.1209/0295-5075/81/20003
Published online 10 December 2007
EPL, 81 (2008) 20003
DOI: 10.1209/0295-5075/81/20003

Efficiency at maximum power: An analytically solvable model for stochastic heat engines

T. Schmiedl and U. Seifert

II. Institut für Theoretische Physik, Universität Stuttgart - 70550 Stuttgart, Germany


received 27 August 2007; accepted in final form 13 November 2007; published January 2008
published online 10 December 2007

Abstract
We study a class of cyclic Brownian heat engines in the framework of finite-time thermodynamics. For infinitely long cycle times, the engine works at the Carnot efficiency limit producing, however, zero power. For the efficiency at maximum power, we find a universal expression, different from the endoreversible Curzon-Ahlborn efficiency. Our results are illustrated with a simple one-dimensional engine working in and with a time-dependent harmonic potential.

PACS
05.40.Jc - Brownian motion.
05.70.Ln - Nonequilibrium and irreversible thermodynamics.
82.70.Dd - Colloids.

© EPLA 2008