arXiv subjects

R. X. Zhai

Publications and source records attributed to R. X. Zhai.

2 recordsLinked to original sources

arXiv2026

Geometric Formulation of Power-Efficiency Bounds in Carnot-like Engines

We formulate the power-efficiency constraint of Carnot-like heat engines as a geometric optimization problem in the plane of normalized branch dissipations. In this plane, efficiency contours are straight lines, so maximizing the efficiency at fixed power reduces to bounding the slope of an admissible line. For branch dissipations that scale inversely with a power of the process time, the fixed-power constraint defines a two-dimensional attainable region, and the resulting slope-bound problem reduces to a linear-programming problem. This geometric framework yields the exact power-efficiency constraint for Carnot-like heat engines with power-law dissipation.

cond-mat.stat-mech↗

arXiv2025

Exact bound of power-efficiency trade-off in finite-time thermodynamic cycles

Power and efficiency are fundamental criteria for evaluating the performance of thermodynamic cycles. However, it is generally impossible to maximize both simultaneously. In particular, achieving maximum efficiency inevitably leads to vanishing power as the cycle duration approaches infinity. A quantitative characterization of this trade-off yields significant theoretical and practical implications. In this letter, we analytically derive an exact bound constraining power and efficiency in low-dissipation finite-time heat engines. This bound specifies the maximum power attainable at any prescribed efficiency, thereby providing a benchmarking for evaluating the performance of heat engines.

cond-mat.stat-mech↗