RCAIDE.Library.Methods.Powertrain.Converters.Engine.compute_throttle_from_power

compute_throttle_from_power#

compute_throttle_from_power(engine, conditions)[source]#

Computes engine throttle setting and fuel consumption based on required power output.

Parameters:
  • engine (RCAIDE.Library.Components.Propulsors) –

    Engine instance with the following attributes:
    • sea_level_powerfloat

      Maximum power output at sea level [W]

    • flat_rate_altitudefloat

      Altitude below which power remains constant [m]

    • power_specific_fuel_consumptionfloat

      Power specific fuel consumption [kg/(W·s)]

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

    Engine operating conditions with:
    • powernumpy.ndarray

      Required power output [W]

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

    Flight conditions with:
    • freestream.altitudenumpy.ndarray

      Current altitude [m]

    • freestream.delta_ISAnumpy.ndarray

      Temperature offset from standard atmosphere [K]

Return type:

None

Notes

This function is the inverse of compute_power_from_throttle, calculating the required throttle setting to achieve a desired power output considering atmospheric conditions.

Major Assumptions
  • Power varies linearly with density ratio above flat-rate altitude

  • Power remains constant below flat-rate altitude

  • Standard atmosphere conditions apply except for ISA temperature offset

  • Minimum power output is zero (negative values are clipped)

Theory

The power available is computed using:

\[P_{available} = P_{SL} \frac{\sigma - 0.117}{0.883}\]

Then throttle is determined by:

\[\text{throttle} = \frac{P_{required}}{P_{available}}\]
where:
  • \(P_{SL}\) is sea-level power

  • \(\sigma\) is the density ratio

  • \(P_{required}\) is the requested power output

References

[1] Gudmundsson, S. (2014). General Aviation Aircraft Design: Applied Methods and Procedures. Butterworth-Heinemann. [2] Gagg and Ferrar