Efficient asymmetric collisional Brownian particle engines

TL;DR

This paper presents a method to optimize Brownian thermal engines using a collisional approach with unequal reservoir interaction times, leading to enhanced efficiency and power in finite-time operations.

Contribution

It introduces a general optimization strategy for Brownian engines based on asymmetric contact times, providing exact expressions for thermodynamic properties and performance improvements.

Findings

Optimized engine performance through asymmetric contact times.

Enhanced efficiency and power output with proper tuning.

Broadened operational regime for Brownian engines.

Abstract

The construction of efficient thermal engines operating at finite times constitutes a fundamental and timely topic in nonequilibrium thermodynamics. We introduce a strategy for optimizing the performance of Brownian engines, based on a collisional approach for unequal interaction times between the system and thermal reservoirs. General (and exact) expressions for thermodynamic properties and their optimized values are obtained, irrespective of the driving forces, asymmetry, the temperatures of reservoirs and protocol to be maximized. Distinct routes for the engine optimization, including maximizations of output power and efficiency with respect to the asymmetry, force and both of them are investigated. For the isothermal work-to-work converter and/or small difference of temperature between reservoirs, they are solely expressed in terms of Onsager coefficients. Although the symmetric engine can operate very inefficiently depending on the control parameters, the usage of distinct contact times between the system and each reservoir not only can enhance the machine performance (signed by an optimal tuning ensuring the largest gain) but also enlarges substantially the machine regime operation. The present approach can pave the way for the construction of efficient Brownian engines operating at finite times.