Micro-/nanoscaled irreversible Otto engine cycle with friction loss and boundary effects and its performance characteristics

An irreversible cycle model of the micro-/nanoscaled Otto engine cycle with internal friction loss is established. The general expressions of the work output and efficiency of the cycle are calculated based on the finite system thermodynamic theory, in which the quantum boundary effect of gas particles as working substance and the mechanical Casimir effect of gas system are considered. It is found that, for a micro-/nanoscaled Otto cycle devices, the work output W and efficiency η of the cycle can be expressed as the functions of the temperature ratio τ of the two heat reservoirs, the volume ratio rV and the surface area ratio rA of the two isochoric processes, the dimensionless thermal wavelength λ and other parameters of cycle, while for a macroscaled Otto cycle devices, the work output W0 and efficiency η0 of the cycle are independent of the surface area ratio rA and the dimensionless thermal wavelength λ. Further, the influence of boundary of cycle on the performance characteristics of the micro-/nanoscaled Otto cycle are analyzed in detail by introducing the output ratio W/W0 and efficiency ratio η/η0. The results present the general performance characteristics of a micro-/nanoscaled Otto cycle and may serve as the basis for the design of a realistic Otto cycle device in micro-/nanoscale.