Obtaining efficient collisional engines via velocity dependent drivings

TL;DR

This paper introduces a velocity-dependent coupling in collisional engines inspired by molecular motors, which significantly enhances efficiency even with large temperature differences, as analyzed through stochastic thermodynamics.

Contribution

It proposes and investigates a novel velocity-dependent coupling mechanism to improve the performance of collisional engines, supported by exact expressions and optimization strategies.

Findings

Optimal coupling substantially increases engine efficiency.

Performance improvement persists even with large temperature differences.

A general argument estimates the optimal coupling regardless of model specifics.

Abstract

Brownian particles interacting sequentially with distinct temperatures and driving forces at each stroke have been tackled as a reliable alternative for the construction of engine setups. However they can behave very inefficiently depending on the driving used for the worksource and/or when temperatures of each stage are very different from each other. Inspired by some models for molecular motors and recent experimental studies, a coupling between driving and velocities is introduced as an alternative ingredient for enhancing the system performance. Here, the role of this new ingredient for levering the engine performance is detailed investigated from stochastic thermodynamics. Exact expressions for quantities and distinct maximization routes have been obtained and investigated. The search of an optimal coupling provides a substantial increase of engine performance (mainly efficiency), even for large $\Delta T$. A simple and general argument for the optimal coupling can be estimated, irrespective the driving and other model details.