Consistency of optimizing finite-time Carnot engines with the low-dissipation model in the two-level atomic heat engine

Yu-Han Ma,C P Sun,Hui Dong

Figure 2. The finite-time Carnot-like cycles for a two-level atomic heat engine with different operation time τh. The red (right) curves represent the high-temperature finite-time quasi-isothermal processes with the duration τh, while the blue (left) curves represent the low-temperature isothermal processes. The adiabatic processes are plotted with the black (horizontal) lines. The outermost dash-dotted curves relate to the quasi-static cycle with τh = 200tr, while the middle dashed cycle and inner solid cycle are obtained with τh = 10tr and τh = 2tr, respectively. In this example, we choose ${\omega }_{{\rm{h}}}^{{\rm{i}}}=1$, ${\omega }_{{\rm{h}}}^{{\rm{f}}}=0.9$, γh = 1, Th = 10, and Tc = 9. ${t}_{{\rm{r}}}={\omega }_{{\rm{h}}}^{{\rm{i}}}/\left(2{\gamma }_{{\rm{h}}}{T}_{{\rm{h}}}\right)=0.05$ is the relaxation time related to the high-temperature finite-time quasi-isothermal process.