Learning Forum

[grigorios.sergentanis]

Hello Community,

I'm trying to solve for the magnetic field homogeneity of an inductor, and would like to evaluate&plot the following expression in a rectangular area.

(B_{y} - B_{y,center})/B_{y,center}

Where B_{y} is the magnetic field density in the y-direction, and that is compared to the value at the center of the air gap. This would appear to be feasible using the fields calculator, and in fact I have created the named expressions as so (please ignore the fact I'm using scalarX commands, as these are just because of the orientation):

However, when evaluating this over the surface of the air-gap, it seems to exist only in the mesh cell that contains the center point (Min/Max values are found very close to the center point, which is definitely wrong). Even when plotting the field on the rectangle, I get a field plot for the specific mesh cell only. If I replace By_Center by its number, and re-do the fields calculation it works fine. 

My problem is, that I would like By_Center to be treated as a pure number, without any geometric associations, when I evaluate over the whole air-gap. Doing the calculations manually would not work for me, as I need to run a lot of parametric analyses on this project. Any ideas would be more than welcome =).

[MirandaH]

Hi, you can read the value of the named expression on each node and export to a txt file from field calculator, is this what you are looking for?

[grigorios.sergentanis]

Hello,

Thank you for getting back to me. This is not quite what I am trying to achieve.

I want to get the expression (B_{y} - B_{y,center})/B_{y,center} plotted all over a non-model rectangle I've drawn. However, the named expression By_Center seen in the original photo, limits the calculation area of any further calculations in the area near the Chamber_Center point, which is in the PointValue() command.

Thus, I cannot plot the named expression "Dev_Per" over my rectangle (which is my area of interest). I get the plot only in the mesh cell containing the point I've defined (Chamber_Center). I can get the field plot over the whole rectangle by enabling surface smoothing, but I'm confident that this yields the wrong results, as I've done the calculator expression by replacing B_{y,center} with the numeric value, and I get a different field plot.

Let me know if there's a way around this, please?