This example is taken from Cornell University’s ANSYS AIM Learning Modules

Learning Goals

In this tutorial, you will learn to:

• Determine magnetic flux density and field intensity in the permanent magnet and the air gap

Problem Specification

A permanent magnet circuit consists of a highly permeable core, a permanent magnet, and an air gap. Determine the magnetic flux density and field intensity in the permanent magnet and the air gap.

Pre-Analysis 

Governing Equation:

Magnetostatics is the study of magnetic fields in devices where the magnetic field is generated from DC (steady) currents and/or permanent magnets.  Magnetostatics is a special case of Maxwell’s equations, which form the basis of electromagnetism.

For magnetostatics the electric field inside of a current carrying coil is completely decoupled from the magnetic field, and the following Maxwell’s equations are solved for magnetostatics –

Where ∇ denotes divergence, H is the magnetic field intensity, J is the current density and B is the magnetic flux density.

Geometry

Download the tutorial file

The following video shows how to import the geometry in Discovery AIM.

Physics Setup

The following video shows how to assign materials and its properties.

Results Evaluation

The following video shows how to compute magnetic flux density.