Eur. Phys. J. B 38, 457-461 (2004)
https://doi.org/10.1140/epjb/e2004-00140-y

Current, maximum power and optimized efficiency of a Brownian heat engine

Department of physics, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia and The Abdus Salam International Centre for Theoretical Physics, 11 Strada Costiera, 34014 Trieste, Italy

Corresponding author: ^a mbekele@phys.aau.edu.et

Received: 29 July 2003
Revised: 28 December 2003
Published online: 28 May 2004

Abstract

A microscopic heat engine is modeled as a Brownian particle in a sawtooth potential (with load) moving through a highly viscous medium driven by the thermal kick it gets from alternately placed hot and cold heat reservoirs. We found closed form expression for the current as a function of the parameters characterizing the model. Depending on the values these model parameters take, the engine is also found to function as a refrigerator. Expressions for the efficiency as well as for the refrigerator performance are also reported. Study of how these quantities depend on the model parameters enabled us in identifying the points in the parameter space where the engine performs with maximum power and with optimized efficiency. The corresponding efficiencies of the engine are then compared with those of the endoreversible and Carnot engines.