Universal constraint for efficiency and power of a low-dissipation heat engine

TL;DR

This paper derives a universal efficiency-power constraint for low-dissipation heat engines, validated with a microscopic model, and links microscopic dynamics to phenomenological parameters for optimizing engine performance.

Contribution

It establishes a universal efficiency-power relation in the low-dissipation regime and connects microscopic dynamics to macroscopic engine parameters.

Findings

Universal efficiency-power constraint derived

Validation with a Carnot-like engine model

Connection between microscopic coupling and phenomenological parameters

Abstract

The constraint relation for efficiency and power is crucial to design optimal heat engines operating within finite time. We find a universal constraint between efficiency and output power for heat engines operating in the low-dissipation regime. Such constraint is validated with an example of Carnot-like engine. Its microscopic dynamics is governed by the master equation. Based on the master equation, we connect the microscopic coupling strengths to the generic parameters in the phenomenological model. We find the usual assumption of low-dissipation is achieved when the coupling to thermal environments is stronger than the driving speed. Additionally, such connection allows the design of practical cycle to optimize the engine performance.