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Unknown variable in COMSOL AC/DC module
Posted 2 déc. 2021, 07:52 UTC−5 1 Reply
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Hi everyone.
I have some problem in AC/DC module with simulation of external surface charge accumulation on dielectric shielding. After defined 4 boundaries wich are surfaces of dielectirc shielding while computing solution appears an error shown below:
Failed to evaluate variable.
- Variable: nF
- Geometry: 1
- Boundary: 4 5 6 12
Failed to evaluate expression.
- Expression: d((test(mod1.es.sigs)*(mod1.es.sigst-nF-nFe)*mod1.es.d)*(dvol),{test@3}).
I have no idea what are this nF and nFe variable. Anyone knows what this nF and nFe means? Best regards Rafał
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Hi Rafał,
I think what will help you out here, is the Equation View in the COMSOL Desktop. It will help you investigate the equations (and variables) used in a physics feature.
In this case, you can see the variables nF and nFe refer to the Normal ion current density and Normal electron current density, respectively.
However, without seeing your model, it is difficult to provide you an anwer about why the error appears. Please send the model to our customer support: https://www.comsol.com/support
Regards, Lipeng