Open-drive detailed expander model


Model ExpanderOpenDriveDetailed represents the expanson of fluid in an open-drive volumetric machine. The evolution of the fluid through the expander is decomposed into six thermodynamic processes, as shown in the figure:

  • Supply pressure drop (su –> su,1)
  • Supply cooling-down (su,1 –> su,2)
  • Isentropic expansion to the internal pressure imposed by the built-in volume ratio of the expander (su,2 –> in)
  • Expansion at a fixed volume to the exhaust pressure (in –> ex,2)
  • Mixing between suction flow and leakage flow (ex,2 –> ex,1)
  • Exhaust cooling-down or heating-up (ex,1 –> ex)


Lemort, V., Quoilin, S., Cuevas, C., & Lebrun, J.. (2009). Testing and modeling a scroll expander integrated into an Organic Rankine Cycle. Applied Thermal Engineering, 29, 3094-3102.