RCAIDE.Library.Methods.Powertrain.Converters.Compression_Nozzle.compute_compression_nozzle_performance

compute_compression_nozzle_performance#

compute_compression_nozzle_performance(compression_nozzle, conditions)[source]#

Computes the performance of a compression nozzle based on its polytropic efficiency.

Parameters:
  • compression_nozzle (Data) –

    Data dictionary with compression nozzle properties
    • tagstr

      Identifier for the compression nozzle

    • pressure_ratiofloat

      Pressure ratio across the nozzle [unitless]

    • polytropic_efficiencyfloat

      Polytropic efficiency of the nozzle [unitless]

    • pressure_recoveryfloat

      Pressure recovery factor [unitless]

    • compressibility_effectsbool

      Flag to include compressibility effects

    • working_fluidData

      Working fluid object with methods to compute properties

  • conditions (Data) –

    Data dictionary with flow conditions
    • freestreamData

      Freestream flow properties - pressure : ndarray

      Freestream pressure [Pa]

      • mach_numberndarray

        Freestream Mach number [unitless]

    • energyData
      Energy conditions
      • convertersdict

        Dictionary of converter conditions indexed by tag - inputs : Data

        Input conditions - stagnation_temperature : ndarray

        Entering stagnation temperature [K]

        • stagnation_pressurendarray

          Entering stagnation pressure [Pa]

        • static_temperaturendarray

          Entering static temperature [K]

        • static_pressurendarray

          Entering static pressure [Pa]

        • mach_numberndarray

          Entering Mach number [unitless]

Returns:

Results are stored in conditions.energy.converters[compression_nozzle.tag].outputs:
  • stagnation_temperaturendarray

    Exit stagnation temperature [K]

  • stagnation_pressurendarray

    Exit stagnation pressure [Pa]

  • stagnation_enthalpyndarray

    Exit stagnation enthalpy [J/kg]

  • mach_numberndarray

    Exit Mach number [unitless]

  • static_temperaturendarray

    Exit static temperature [K]

  • static_enthalpyndarray

    Exit static enthalpy [J/kg]

  • velocityndarray

    Exit nozzle velocity [m/s]

  • static_pressurendarray

    Exit static pressure [Pa]

Return type:

None

Notes

This function computes the thermodynamic properties at the exit of a compression nozzle based on the inlet conditions and nozzle characteristics. It handles both subsonic and supersonic flows with appropriate relations.

Major Assumptions
  • Pressure ratio and polytropic efficiency do not change with varying conditions

  • Adiabatic process

  • Subsonic or choked output

Theory The compression nozzle performance is calculated using gas dynamics relations for compressible flow. For subsonic flow, isentropic relations are used. For supersonic flow, normal shock relations are applied. The stagnation properties are transformed to static properties based on the exit Mach number.

References

[1] Stanford University, “AA283 Course Notes”, https://web.stanford.edu/~cantwell/AA283_Course_Material/AA283_Course_Notes/