Experimental validation of the $1/\tau$ -scaling entropy generation in finite-time thermodynamics with dry air

TL;DR

This paper experimentally validates the $1/ au$ scaling law of entropy generation in finite-time thermodynamics using dry air, and demonstrates optimized control protocols to minimize entropy production, aiding heat engine design.

Contribution

It provides the first direct experimental validation of the $1/ au$ entropy scaling law and confirms the effectiveness of optimized control protocols in reducing entropy generation.

Findings

Confirmed $1/ au$ scaling law experimentally

Demonstrated optimized control protocol reduces entropy generation

Provides insights for practical heat engine cycle design

Abstract

The second law of thermodynamics can be described as the non-decreasing of the entropy in the irreversible thermodynamic process. Such phenomenon can be quantitatively evaluated with the irreversible entropy generation (IEG), which was recently found to follow a $1/\tau$ scaling for the system under a long contact time $\tau$ with the thermal bath. This scaling, predicted in many finite-time thermodynamic models, is of great potential in the optimization of heat engines, yet remains lack of direct experimental validation. In this letter, we design an experimental apparatus to test such scaling by compressing dry air in a temperature-controlled water bath. More importantly, we quantitatively verify the optimized control protocol to reduce the IEG. Such optimization shall bring new insight to the practical design of heat engine cycles.