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How to change Values for "Terminal"-Type Boundary Conditions

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Hey,

I want to model a capacitively coupled quadrupole for imaging over a finite sample using the AC/DC module with electric currents in frequency domain.

For this purpose I would like to do something similar as in the "Geoelectrics - Forward Problem and Sensitivity", Model ID: 9636, so changing the points for the current source.

However, instead of using point sources, I use the "Terminal"-Type boundary condition. The current I is defined as:

Ic*(dom==dom_C1), Ic - injection current, dom_C1 - terminal boundary number
-Ic*(dom==dom_C2)

where the first equation is for Terminal 1 and the second for Terminal 2.

For the solver, I used "Parametric Sweep", with parameter names "dom_C1" and "dom_C2" and as parameters the corresponding boundary values (e.g. "167 179 166 175").

However, when Comsol tries to assembly the equations I get an error:

"Failed to evaluate variable.
- Variable: dom
- Global scope
Failed to evaluate variable.
- Variable mod1.ec.I0_S1
- Defined as: (Ic*((-(dom==dom_C1))
Failed to evaluate expression.
- Expression: mod1.ec.I0_S1"

Could anybody help me on how to set up Comsol to evaluate a whole set of different source positions.

Thanks for your help!

0 Replies Last Post Mar 20, 2012, 7:51 a.m. EDT
COMSOL Moderator

Hello Sebastian Uhlemann

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