Discussion Forum

Hi, I'm a fairly new COMSOL user. I am modeling a simple solenoid with active shielding coils in Multiphysics AC/DC module and have validated my model (I know it is solving for the correct field profile). My problem is when performing the 2D surface mapping of the magnetic flux density (mf.normB): specifically I would like to visualize the 10 G (gauss) line. I attempted to manually alter my "range" in the surface plot settings, however when I set 10 G (0.001 T) as my minimum for the data range, my entire volume remains visible (I know this is not the case, based on my 1D analysis). When I play with the minimum, alternating between 0.001 and 0.02 in 0.001 increments (0.001, 0.002, 0.003, etc), I see a change at 0.004 and then another change at 0.015, but no change to the boundary in between. I know physically this is not accurate, so I am trying to figure out what sort of parameters I need to change in order to improve precision. I include some images showing the field map with the default data ranges, as well as when setting the limit to 0.001, 0.004, 0.015 T. I also include my mesh, which is set as 0.002 m in the "critical" volumes (coils, magnet aperture, and beamline to neighboring component). I tried one iteration with an extremely fine mesh over the full volume but this did not solve the problem and made solutions very time consuming. Thanks, Melanie!!