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Space Charge Density Coupling - undefined variable
Posted 2018年6月15日 GMT-4 05:59 Chemical Reaction Engineering, Electrochemistry, Parameters, Variables, & Functions 0 Replies
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Dear Community,
in my application I try to model a simple problem of migration/diffusion of ions in an electrical field (twi species like Sodium and Chlorite). Therefore, I use the Nernst-Planck-Poisson Equations. In COMSOL I try using the implemented electrostatic(es) and Transport of diluted species(tds) models. For getting correct results, I need to couple those two. The Multiphysics knot suggests me "Potential Coupling (pc1)" and "Space Charge Density Coupling (scdc1)". Makes sense to me.
However, when I want to compute the problem it shows me the error: Undefined variable. - Variable: comp1.scdc1.rhoq - Geometry: geom1 - Domain: 1
...obviously meaning that a definition of at least one variable is missing for the Space Charge Density Coupling.
I use a Time-Dependant Solver, Fully Coupled, Direct. The scdc1-knot tells me that the coupled source interface is the "tds" and the destination is the "es".
I use COMSOL 5.3 and Win10.
In my opinion I defined every necessary variable. Someone has a clue what I could be missing?
Attached you find my .mph file.
Attachments:
Hello Ulrich
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