RCAIDE.Library.Mission.Segments.Descent.Linear_Mach_Constant_Rate

Linear_Mach_Constant_Rate

Functions

initialize_conditions(segment)

Initializes conditions for linear Mach descent at fixed rate

initialize_conditions(segment)

Initializes conditions for linear Mach descent at fixed rate

Parameters:

segment (Segment) –

The mission segment being analyzed

• descent_ratefloat

  Rate of descent [m/s]

• mach_number_startfloat

  Initial Mach number [-]

• mach_number_endfloat

  Final Mach number [-]

• altitude_startfloat

  Initial altitude [m]

• altitude_endfloat

  Final altitude [m]

• sideslip_anglefloat

  Aircraft sideslip angle [rad]

• state:

  numerics.dimensionless.control_pointsarray

  Discretization points [-]

  conditionsData

  State conditions container

  initialsData, optional

  Initial conditions from previous segment

Return type:

None

Notes

This function sets up the initial conditions for a descent segment with linearly varying Mach number and constant descent rate. The true airspeed varies with both Mach number and local speed of sound. Updates segment with velocity vector, position vector, and altitude.

Calculation Process

1. Get atmospheric properties for speed of sound

2. Discretize altitude profile

3. Calculate Mach number variation: M = M0 + (Mf - M0)*t where:

• M0 is initial Mach number

• Mf is final Mach number

• t is normalized time/distance

4. Calculate true airspeed:

   V = M * a where:

   • M is local Mach number

   • a is local speed of sound

5. Decompose velocity using:

   • Fixed descent rate

   • Sideslip angle

   • Computed true airspeed

Major Assumptions

• Linear Mach number variation

• Constant descent rate

• Standard atmosphere model

• Small angle approximations

• Quasi-steady flight

See also

RCAIDE.Framework.Mission.Segments, RCAIDE.Library.Mission.Common.Update.atmosphere