RCAIDE.Library.Methods.Powertrain.Propulsors.Turbofan.size_core

size_core

size_core(turbofan, conditions)

Sizes the core flow for a turbofan engine at the design condition by computing the non-dimensional thrust.

Parameters:

• turbofan (RCAIDE.Library.Components.Propulsors.Turbofan) –

  Turbofan engine component with the following attributes:

  • tagstr

    Identifier for the turbofan

  • 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]

  • bypass_ratiofloat

    Bypass ratio of the turbofan

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

  Flight conditions with:

  • freestreamData

    Freestream properties

    • speed_of_soundnumpy.ndarray

      Speed of sound [m/s]

  • energy.propulsors[turbofan.tag]Data

    Turbofan-specific conditions

    • bypass_rationumpy.ndarray

      Bypass ratio

    • total_temperature_referencenumpy.ndarray

      Reference total temperature [K]

    • total_pressure_referencenumpy.ndarray

      Reference total pressure [Pa]

    • throttlefloat

      Throttle setting [0-1]

    • thrust_specific_fuel_consumptionnumpy.ndarray

      Thrust specific fuel consumption [kg/(N·s)]

    • non_dimensional_thrustnumpy.ndarray

      Non-dimensional thrust

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, accounting for the bypass ratio.

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, non-dimensional thrust, and bypass ratio:

\[\dot{m}_{core} = \frac{F_{design}}{F_{sp} \cdot a_0 \cdot (1 + BPR) \cdot \text{throttle}}\]

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/

See also

RCAIDE.Library.Methods.Powertrain.Propulsors.Turbofan.compute_thurst