Domain, Boundary, Point, and Pair Nodes for the Magnetic Fields Interface
The Magnetic Fields interface has these domain, boundary, point, and pair nodes available, which are listed in alphabetical order.
About the Boundary Conditions
With no surface currents present, the physics interface conditions
need to be fulfilled. Because A is being solved for, the tangential component of the magnetic potential is always continuous, and thus the first condition is automatically fulfilled. The second condition is equivalent to the natural boundary condition and is hence also fulfilled unless surface currents are explicitly introduced.
Table 5-1 lists the interior and exterior boundary conditions available with this physics interface.
Table 5-1: Interior and Exterior Boundary Conditions for the Magnetic Fields Interface
Node
Interior
Exterior
External Magnetic Vector Potential
x
x
Impedance Boundary Condition
 
x
Lumped Port
x
x
Magnetic Field
 
x
Magnetic Insulation
x
x
Magnetic Potential
x
x
Magnetic Shielding
x
 
Perfect Magnetic Conductor
x
x
Periodic Condition
 
x
Surface Current Density
x
x
Surface Magnetic Current Density
x
x
Thin Low Permeability Gap
x
 
Transition Boundary Condition
x
 
Available Nodes
These nodes, listed in alphabetical order, are available from the Physics ribbon toolbar (Windows users), Physics context menu (Mac or Linux users), or by right-clicking to access the context menu (all users).
In general, to add a node, go to the Physics toolbar no matter what operating system you are using. Subnodes are available by clicking the parent node and selecting it from the Attributes menu.
Also see Table 5-1 for a list of interior and exterior boundary conditions.
•
Ampère’s Law
•
Ampère’s Law, Magnetostrictive
•
Boundary Feed
•
Coil Geometry
•
Edge Current
•
Electric Point Dipole
•
External Current Density
•
External Magnetic Vector Potential
•
Force Calculation (described for the Electrostatics interface)
•
Gap Feed
•
Harmonic Perturbation
•
Impedance Boundary Condition
•
Initial Values
•
Line Current (Out-of-Plane)
•
Lumped Port
•
Magnetic Field
•
Magnetic Insulation (the default boundary condition)
•
Magnetic Point Dipole
•
Magnetic Point Dipole (on Axis)
•
Magnetic Potential
•
Magnetic Shielding
•
Coil
•
Perfect Magnetic Conductor
•
Lumped Port
•
Sector Symmetry
•
Single-Turn Coil
•
Surface Current Density
•
Surface Magnetic Current Density
•
Thin Low Permeability Gap
•
Transition Boundary Condition
•
Velocity (Lorentz Term)
For 2D axisymmetric components, the COMSOL software takes the axial symmetry boundaries (at r = 0) into account and adds an Axial Symmetry node to the component that is valid on the axial symmetry boundaries only.
Infinite Elements, Perfectly Matched Layers, and Absorbing Layers in the COMSOL Multiphysics Reference Manual
In the COMSOL Multiphysics Reference Manual, see Table 2-4 for links to common sections and Table 2-5 for common feature nodes. You can also search for information: press F1 to open the Help window or Ctrl+F1 to open the Documentation window.