RCAIDE.Library.Methods.Powertrain.Propulsors.Turbojet.size_core

size_core#

size_core(turbojet, conditions)[source]#

Sizes the core flow for a turbojet engine at the design condition.

Parameters:
  • turbojet (RCAIDE.Library.Components.Propulsors.Turbojet) –

    Turbojet engine component with the following attributes:
    • tagstr

      Identifier for the turbojet

    • reference_temperaturefloat

      Reference temperature for mass flow scaling [K]

    • reference_pressurefloat

      Reference pressure for mass flow scaling [Pa]

    • design_thrustfloat

      Design thrust at the design point [N]

  • conditions (RCAIDE.Framework.Mission.Common.Conditions) –

    Flight conditions with:
    • freestreamData
      Freestream properties
      • speed_of_soundnumpy.ndarray

        Speed of sound [m/s]

    • energy.propulsors[turbojet.tag]Data
      Turbojet-specific conditions
      • total_temperature_referencenumpy.ndarray

        Reference total temperature [K]

      • total_pressure_referencenumpy.ndarray

        Reference total pressure [Pa]

      • non_dimensional_thrustnumpy.ndarray

        Non-dimensional thrust

Returns:

Results are stored in the turbojet object:
  • design_mass_flow_ratefloat

    Core mass flow rate at design point [kg/s]

  • compressor_nondimensional_massflowfloat

    Non-dimensional mass flow parameter [kg·√K/(s·Pa)]

Return type:

None

Notes

This function determines the core mass flow rate required to produce the design thrust at the specified design conditions. It uses the non-dimensional thrust parameter to scale the mass flow appropriately.

Major Assumptions
  • Perfect gas behavior

  • Design point is at maximum throttle (throttle = 1.0)

Theory The core mass flow rate is calculated from the design thrust and non-dimensional thrust:

\[\dot{m}_{core} = \frac{F_{design}}{F_{sp} \cdot a_0 \cdot \text{throttle}}\]

The non-dimensional mass flow parameter is then calculated:

\[\dot{m}_{hc} = \frac{\dot{m}_{core}}{\sqrt{\frac{T_{ref}}{T_{t,ref}}} \cdot \frac{P_{t,ref}}{P_{ref}}}\]

References

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