The Magnetic Fields, No Currents, Boundary Elements (mfncbe) interface (), found under the AC/DC>Magnetic Fields, No Currents branch when adding a physics interface, is used to compute magnetostatic fields from permanent magnets and other current free magnetic sources. It can also be coupled to The Magnetic Fields, Currents Only Interface or The Magnetic Fields Interface to account for outer, current free regions as an alternative to using Infinite Elements. The formulation is stationary. The physics interface solves Gauss’ Law for the magnetic field using the scalar magnetic potential as the dependent variable.

When this physics interface is added, these default nodes are also added to the Model Builder — Magnetic Flux Conservation, Magnetic Insulation (on exterior boundaries), and Initial Values. Then, from the Physics toolbar, add other nodes that implement, for example, magnetic scalar potential and magnetic flux density conditions. You can also right-click Magnetic Fields, No Currents, Boundary Elements to select physics features from the context menu.

The physics-controlled mesh is controlled from the Mesh node’s Settings window (if the Sequence type is Physics-controlled mesh). There, in the table in the Physics-Controlled Mesh section, find the physics interface in the Contributor column and select or clear the check box in the Use column on the same table row for enabling (the default) or disabling contributions from the physics interface to the physics-controlled mesh.

From the Selection list, select any of the options — Manual, All domains, All voids, or All domains and voids (the default). The geometric entity list displays the selected domain entity numbers. Edit the list of selected domain entity numbers using the selection toolbar buttons to the right of the list or by selecting the geometric entities in the Graphics window. Entity numbers for voids can be entered by clicking the Paste () button in the selection toolbar and supplying the entity numbers in the in the dialog box. The entity number for the infinite void is 0, and finite voids have negative entity numbers.

Selections can also be entered using the Selection List window, available from the Windows menu on the Home toolbar.

Select the Enable physics symbols check box to display symmetry planes (in 3D) and lines (in 2D) in the Graphics window, as specified in the Symmetry settings.

To display this section, click the Show More Options button () and select Advanced Physics Options.

To display this section, click the Show More Options button () and select Advanced Physics Options.

For 2D components, enter a default value for the Out-of-plane thickness d (SI unit: m). The default value of 1 unit length is typically not representative for a thin domain. Instead it describes a unit thickness that makes the 2D equation identical to the equation used for 3D components.

From the Magnetic scalar potential/Magnetic flux density list, choose from predefined options for the boundary element discretization order for the magnetic scalar potential variable and the magnetic flux density variable, respectively. The predefined options represent the suitable combinations of element orders such as Quadratic/Linear (the default).

The settings under Value types when using splitting of complex variables are important for sensitivity and optimization computations. See the description of the built-in operators fsens and fsensimag.

The dependent variable (field variable) is for the Magnetic scalar potential Vm. The name can be changed but the names of fields and dependent variables must be unique within a model.