RCAIDE.Library.Mission.Segments.Untrimmed.Untrimmed.initialize_conditions

initialize_conditions(segment)

Initializes conditions for untrimmed flight analysis at fixed state

Parameters:

segment (Segment) –

The mission segment being analyzed

• altitudefloat

  Flight altitude [m]

• air_speedfloat

  True airspeed [m/s]

• sideslip_anglefloat

  Aircraft sideslip angle [rad]

• linear_acceleration_xfloat

  Acceleration in x-direction [m/s^2]

• linear_acceleration_yfloat

  Acceleration in y-direction [m/s^2]

• linear_acceleration_zfloat

  Acceleration in z-direction [m/s^2]

• roll_ratefloat

  Aircraft roll rate [rad/s]

• pitch_ratefloat

  Aircraft pitch rate [rad/s]

• yaw_ratefloat

  Aircraft yaw rate [rad/s]

• state:

  conditionsData

  State conditions container

  initialsData, optional

  Initial conditions from previous segment

Returns:

Updates segment conditions directly:

• conditions.freestream.altitude [m]

• conditions.frames.inertial.position_vector [m]

• conditions.frames.inertial.velocity_vector [m/s]

• conditions.frames.inertial.acceleration_vector [m/s^2]

• conditions.static_stability.roll_rate [rad/s]

• conditions.static_stability.pitch_rate [rad/s]

• conditions.static_stability.yaw_rate [rad/s]

Return type:

None

Notes

This function sets up the initial conditions for an untrimmed flight analysis at fixed speed and altitude. It allows specification of full 6-DOF motion states without enforcing trim constraints.

Calculation Process

1. Check initial altitude

2. Decompose velocity into components using sideslip angle:

   • v_x = V * cos(β)

   • v_y = V * sin(β)

   where: - V is true airspeed - β is sideslip angle

3. Set position and altitude

4. Set full acceleration vector

5. Set angular rates

Major Assumptions

• Fixed speed and altitude point

• No trim constraints enforced

• Full 6-DOF motion allowed

• Small angle approximations

• No atmospheric variations

See also

RCAIDE.Framework.Mission.Segments