Magnet
The Magnet node is used to model one or multiple magnets, simplifying the definition of the magnetization direction in each magnet. In configurations with electric conductivity, this feature allows for imposing electrical insulation on boundaries, making it easier to compute losses in segmented magnets. It is also possible to add a Loss Calculation subfeature in order to compute induced losses. In the The Rotating Machinery, Magnetic Interface, this feature is called Conducting Magnet.
Magnet
Direction Method
Select the Direction method to be used for determining the direction of the magnetization in the magnet. Choose between:
Specify north and south boundaries, where the north and south boundaries of the magnet can be selected. The direction of the magnetization is then calculated based on the position average of each pole.
Specify by domains, which allows the magnetization direction to be set individually in different subselections of the Magnet feature. The magnetization in each such domain can then be set by either specifying the north and south boundaries, or by entering a user defined direction.
User defined, which allows the user to manually specify a direction vector for the magnetization.
Pattern Type
This section is only available when Specify north and south boundaries is selected as the Direction method. The setting makes it possible to automatically set the magnetization direction for multiple magnets following a certain pattern. Choose between No pattern, Circular pattern, and Linear pattern (or domain index based). When Circular pattern is selected, the magnetization direction for each pattern element is determined by its position in a circle and a pattern repetition angle. Select Linear pattern (or domain index based) to repeat the definition of the magnetization direction in a selection of magnets that are linearly displaced.
Type of Periodicity
This section is only available when Circular pattern or Linear pattern (or domain index based) is chosen as the Pattern type. The different options are Repeating, Alternating, and User defined. When Repeating is selected, the magnetization direction is the same in each element. Select Alternating to instead have the magnetization direction reversed for each repeated element in the pattern. If the alternating pattern is applied to an odd number of magnets, the north and south boundaries should be specified for the first magnet in the pattern. The User defined option is only available for a circular pattern and allows a custom input that determines how much the magnetization direction should change between each element.
Pattern Additional Angle
This section is only available when User defined is chosen as the Type of periodicity, when also having Circular pattern as the Pattern type. This angle is added to the magnetization direction for each repetition in the pattern.
Pattern Center
This section is only available when Circular pattern is chosen as the Pattern type. It defines the center of the circular pattern.
Pattern Axis
This section is only available when Circular pattern is chosen as the Pattern type. This setting is only available in 3D, and defines the axis around which the pattern is created.
Direction of Magnetization
This section is only available when User defined is selected as the Direction method in the Magnet feature. This input vector is equivalent to the one that can be added when Magnetization is selected in the Ampère’s Law feature.
Constitutive Relation B-H
This section is identical to the one in the Ampère’s Law node, apart from that only the options Remanent flux density and Nonlinear permanent magnet are available here.
Constitutive Relation Jc-E
This first part of this section is identical to the one in the Ampère’s Law node, when Electrical conductivity is chosen as the Conduction model. There is also an additional setting here, called Constrain for induced currents, that determines which boundaries are electrically insulated. The different options are Within each domain, No induced current constrain, Within each connected component, and Within all domains. Selecting Within each domain electrically insulates each selected domain separately, and constrains the currents within. Choosing No induced current constrain places no constraint on the induced currents. The option Within each connected component instead constrains the currents in each subselection of domains that are geometrically connected. For example, two adjacent domains will be electrically insulated around their outer common boundary, while for domains that are separated the effect will be the same as when selecting Within each domain. When selecting Within all domains, the net current of all selected domains will be constrained to zero. This setting is only available in 2D, and can be thought of as all of the domains being electrically connected outside of the plane. With this setting there can be a nonzero net current in some domains, but it will be equalized by currents in the opposite direction in other domains.