Problems and Challenges

• Special components necessary:
  • cylinder model = volume with a mechanical flange
  • compressor uses constant c_p
    • instead use constant entropy with c_p(T)
    • needs inversion of nonlinear function
  • turbine using water (TFS-Lib turbine only uses ideal gas)
• Parameter Tuning:
  • reverse logic
    • p, T, given
    • compressor, turbine and heater parameters needed
  • arbitrary guess values → "Failed to solve nonlinear system"
  • solution methods
    • use turbine equations to compute ω or τ manually
    • start with smaller state changes
    • use known state values as initial values
  • model runs at least for a short time
    • → apply parameter changes and monitor results
    • → final values can be reached
  • more details in
    • "Implementing Thermodynamic Cyclic Processes Using the DLR Thermofluid Stream Library",
      SNE 33/4 (2023), 175-182.