Discussion Forum

Hi,

I am trying to create a model to compute the mangetic field around a single coil, in 3D. I completed a model, however the field COMSOL produces is always lower than the analytical solution at the same point.

This is particlarly true for regions near the boundry, where I specify a 'magnetic insulation' boundary condition.

I am doing experiments where we are interested in finding the magnetic field, at a distance of more than 2 diameters from the coil. I am finding that the boundary conditions may be altering the magnetic field strength in the regions near the boundary. Away from the boundary the magnetic field strength is close to the analytical predicition, whereas near the boundary, the field is notably lower than it should be.

I have tried using infinite elements on the sphere boundary defining the solution space, however after computing, the magnetic field strength is much, much lower than it should be.

Can someone expalin to me how I would use 'infinite elemnts' boundary conditions, so that the field is accurate near the model boundary?

I have attached the model below, without 'infinite elements' as I am unsure how to apply them successfully. I am really looking for a robust model for a single current carrying coil, that agrees strongly with analytical results.

regards,
Jonathon