Boundary Load

Use a to apply traction or pressure to boundaries.

Select a — , or to specify the load in the appropriate frame.

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Since the rotor is modeled in a rotating frame in a Solid Rotor interface, a stationary load in a frame works as a stationary load in the model. A stationary load in the frame will, however, change its direction with the angular velocity of the rotor, and therefore acts as a time-dependent load in the model.

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In the Solid Rotor, Fixed Frame interface the above behavior of the loads in different frames is interchanged.

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For a frequency domain analysis, a load in the frame is shifted with the rotor’s phase to give the effect of rotation in the Solid Rotor interface.

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Similarly, a load in the frame is shifted with the rotor’s phase for a frequency domain analysis to give the effect of rotation in the Solid Rotor, Fixed Frame interface.

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For a stationary analysis, has no influence on the analysis.

Force

Select a — , , or . Then enter values or expressions for the load components based on the selection.

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For , you can define a distributed force over the selected boundary.

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For , COMSOL Multiphysics then divides the total force by the area of the surfaces where the load is active.

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For , a scalar input is given, and the orientation of the load is given by the normal to the boundary. The pressure is positive when directed toward the solid.


	After selecting a Load type, the Load list normally only contains User defined. When combined with another physics interface that can provide this type of load, it is also possible to choose a predefined load from this list.


Load Type	variable	SI unit
Load defined as force per unit area	FA	N/m2
Total force	Ftot	N
Pressure	p	Pa

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You can add the Phase subnode to specify the phase of this load in a frequency domain analysis.

Location in User Interface

Context Menus

Ribbon

Physics tab with selected: