Translations:Thermodynamic and Mechanical Study/506/en

The cycle is described by four successive kinematic and thermodynamic regimes: compression, transfer through $H_o$, expansion, and transfer through $H_i$. These phases describe the dominant evolution of the machine; they are not defined by the state of the check valves. Valve opening and closing remain determined independently by the instantaneous pressure differences and may occur within a phase rather than exactly at a phase boundary.