RCAIDE.Library.Mission.Segments.Descent.Constant_CAS_Constant_Rate.initialize_conditions#

initialize_conditions(segment)[source]#

Initializes conditions for constant calibrated airspeed descent at fixed rate

Parameters:

segment (Segment) –

The mission segment being analyzed
  • descent_ratefloat

    Rate of descent [m/s]

  • calibrated_air_speedfloat

    Calibrated airspeed to maintain [m/s]

  • altitude_startfloat

    Initial altitude [m]

  • altitude_endfloat

    Final altitude [m]

  • sideslip_anglefloat

    Aircraft sideslip angle [rad]

  • temperature_deviationfloat

    Temperature offset from standard day [K]

  • state:
    numerics.dimensionless.control_pointsarray

    Discretization points [-]

    conditionsData

    State conditions container

  • analyses:
    atmosphereModel

    Atmospheric model for property calculations

Return type:

None

Notes

This function sets up the initial conditions for a descent segment with constant calibrated airspeed (CAS) and constant descent rate. It handles the conversion between CAS and true airspeed accounting for pressure and density variations with altitude. Updates segment conditions directly with velocity_vector [m/s], altitude [m], and position_vector [m].

Calculation Process
  1. Discretize altitude profile

  2. Get atmospheric properties at each altitude

  3. Convert CAS to true airspeed using:
    • Pressure ratio (δ)

    • Compressibility effects

    • Equivalent airspeed (EAS) conversion

  4. Decompose velocity into components using:
    • Fixed descent rate

    • Sideslip angle

    • Computed true airspeed

Major Assumptions
  • Constant calibrated airspeed

  • Constant descent rate

  • Standard atmosphere model with temperature deviation

  • Small angle approximations

  • Quasi-steady flight