WOLFRAM SYSTEM MODELER

# VariableMassBody

Rigid body with variable mass and inertia tensor

# Wolfram Language

In[1]:=
`SystemModel["Aircraft.Physical.FixedWing.Parts.Propulsions.EnergyStorages.TankSystem.VariableMassBody"]`
Out[1]:=

# Information

This is a model of a rigid body with variable mass and variable inertia tensor, and it solves the Newton—Euler equations for applying forces at the frame_a connector. This model is modified from the Modelica Standard Library Body model such that the mass and inertia tensors are not parameters but variables.

# Parameters (14)

animation Value: true Type: Boolean Description: = true, if animation shall be enabled (show cylinder and sphere) Value: Type: Position[3] (m) Description: Vector from frame_a to center of mass, resolved in frame_a Value: false Type: Boolean Description: = true, if angles_start are used as initial values, else as guess values Value: {0, 0, 0} Type: Angle[3] (rad) Description: Initial values of angles to rotate frame_a around 'sequence_start' axes into frame_b Value: {1, 2, 3} Type: RotationSequence Description: Sequence of rotations to rotate frame_a into frame_b at initial time Value: false Type: Boolean Description: = true, if w_0_start are used as initial values, else as guess values Value: {0, 0, 0} Type: AngularVelocity[3] (rad/s) Description: Initial or guess values of angular velocity of frame_a resolved in world frame Value: false Type: Boolean Description: = true, if z_0_start are used as initial values, else as guess values Value: {0, 0, 0} Type: AngularAcceleration[3] (rad/s²) Description: Initial values of angular acceleration z_0 = der(w_0) Value: world.defaultBodyDiameter Type: Diameter (m) Description: Diameter of sphere Value: sphereDiameter / Types.Defaults.BodyCylinderDiameterFraction Type: Diameter (m) Description: Diameter of cylinder Value: {1, 2, 3} Type: RotationSequence Description: Sequence of rotations to rotate world frame into frame_a around the 3 angles used as potential states Value: Modelica.Mechanics.MultiBody.Frames.axesRotations(sequence_start, angles_start, zeros(3)) Type: Orientation Description: Orientation object from world frame to frame_a at initial time Value: Frames.resolve2(R_start, z_0_start) Type: AngularAcceleration[3] (rad/s²) Description: Initial values of angular acceleration z_a = der(w_a), i.e time derivative of angular velocity resolved in frame_a

# Inputs (10)

m Type: Mass (kg) Description: Mass of rigid body Default Value: 0.001 Type: Inertia (kg⋅m²) Description: (1,1) element of inertia tensor Default Value: 0.001 Type: Inertia (kg⋅m²) Description: (2,2) element of inertia tensor Default Value: 0.001 Type: Inertia (kg⋅m²) Description: (3,3) element of inertia tensor Default Value: 0 Type: Inertia (kg⋅m²) Description: (2,1) element of inertia tensor Default Value: 0 Type: Inertia (kg⋅m²) Description: (3,1) element of inertia tensor Default Value: 0 Type: Inertia (kg⋅m²) Description: (3,2) element of inertia tensor Default Value: Modelica.Mechanics.MultiBody.Types.Defaults.BodyColor Type: Color Description: Color of sphere Default Value: sphereColor Type: Color Description: Color of cylinder Default Value: world.defaultSpecularCoefficient Type: SpecularCoefficient Description: Reflection of ambient light (= 0: light is completely absorbed)

# Connectors (1)

frame_a Type: Frame_a Description: Coordinate system fixed at body

# Components (4)

R_start Type: Orientation Description: Orientation object from world frame to frame_a at initial time Type: World Description: World coordinate system + gravity field + default animation definition Type: Shape Description: Visualizing an elementary object with variable size; all data have to be set as modifiers (see info layer) Type: Shape Description: Visualizing an elementary object with variable size; all data have to be set as modifiers (see info layer)

# Used in Components (1)

 TankSystem Aircraft.Physical.FixedWing.Parts.Propulsions.EnergyStorages Model for fuel tank system