Home / Technical Notes / Magnetic analysis / Size of Ambient Air in Magnetic Analysis

Size of Air Domain in Magnetic Analysis

The air domain needs to be large enough for the magnetic field to decay sufficiently.

Recommended sizes are as follows.

• If a structure is open magnetic circuit such as air-core coil where the magnetic field lines leak outside,
  the distance from the calculated structure to the boundary of the ambient air is recommended to be 2 to 5 times the length of the object.

• If a structure is closed magnetic circuit like a coil having a magnetic core where the magnetic field lines are mostly retained inside,
  the distance from the calculated structure to the boundary of the ambient air is recommended to be 1 to 1.5 times the length of the object.
  

If air domain body is created automatically, its size can be adjusted in the [Air Domain Creation] on the [Mesh tab].

To perform the simulation effectively for the open magnetic circuit, make the air domain large and apply rough meshes there.

 

• With this size, the type of outer boundary condition doesn't make much difference on the results.