Discussion Forum

Hello:

Does anyone know if it is possible in COMSOL to compute the integration of a field variable over a a cross-section area and get this integration for all values of the coordinate along the axis perpendicular to the cross-section area?

I was working in 2D axisymmetry, I revolved the model, did the extrusion coupling variables and now I have the model in 3D, with the circular cross-section in x-z and thy symmetry axis on y-axis. I am trying to get the magnetic flux, but I can only do integration over the boundaries.

What I would like to get is something like this

In 2D

Z value Integration of field variable over cross-section perpendicular to z

z1 value 1
z2 value 2
. .
. .
. .
zn value n


The COMSOL user guide shows several ways for integration, but not for this. There are boundary integration, sub domain integration, volume integration. If I compute boundary integration I can only get 2 values over the cross-section: one for each end of the cylinder. I need the value of the integration along the symmetry axis to later obtain a plot of the integration vs the z values (z is the symmetry axis in 2D, and y is the symmetry axis in 3D, I mean, the axis on which the cylinder axis is).

I tried to draw the rectangle for the cylinder in 2D axisymmetry as many small and thinner rectangles in order to have more boundaries and got at least discrete values of the integration, it is, the value of the integration over the cross-section area for some values of z (the values of z where the boundaries of the thinner rectangles are) but there should be another way.

Sometimes the value of the integration yields a negative result, but I think it's because some vectors are going in the negative direction inside the same area of integration. Anyway, any comments about this last topic is also welcome.

I am attaching an estimated plot in excel because I still trying to do this in COMSOL.

THANK YOU VERY MUCH! I REALLY APPRECIATE YOUR HELP!!!