Title
Maximal power output of a stochastic thermodynamic engine
Abstract
Classical thermodynamics aimed to quantify the efficiency of thermodynamic engines, by bounding the maximal amount of mechanical energy produced, compared to the amount of heat required. While this was accomplished early on, by Carnot and Clausius, the more practical problem to quantify limits of power that can be delivered, remained elusive due to the fact that quasistatic processes require infinitely slow cycling, resulting in a vanishing power output. Recent insights, drawn from stochastic models, appear to bridge the gap between theory and practice in that they lead to physically meaningful expressions for the dissipation cost in operating a thermodynamic engine over a finite time window. Indeed, the problem to optimize power can be expressed as a stochastic control problem. Building on this framework of stochastic thermodynamics we derive bounds on the maximal power that can be drawn by cycling an overdamped ensemble of particles via a time-varying potential while alternating contact with heat baths of different temperature (Tc cold, and Th hot). Specifically, assuming a suitable bound M on the spatial gradient of the controlling potential, we show that the maximal achievable power is bounded by M8(ThTc−1). Moreover, we show that this bound can be reached to within a factor of (ThTc−1)∕(ThTc+1) by operating the cyclic thermodynamic process with a quadratic potential.
Year
DOI
Venue
2021
10.1016/j.automatica.2020.109366
Automatica
Keywords
DocType
Volume
Non-equilibrium thermodynamics,Optimal transportation,Mean-field optimal control
Journal
123
Issue
ISSN
Citations 
1
0005-1098
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Fu Rui100.34
Taghvaei Amirhossein200.34
Yongxin Chen39931.89
Tryphon T. Georgiou421136.71