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Exact calculation of electrical current from current density

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Hello everybody,

I am using comsol to model a bipolar probe with three surfaces : Conductive surface forced to 0V, conductive surface forced to 10V and insulation surface beetween the two conductive surfaces. The probe is put on sea water.

So when i resolve my system I have streamlines between the two condictive surfaces.

Now, I want to calculate the current on each conductive surface from the current density integration. I use the following expression ( ec.Jxnx+ec.Jyny+ec.Jz*nz ).

I have a difference between the current IN and the current OUT about 1%. So I change the mesh to have a more accurate result but I realized that the current is totaly different comparing to the first mesh. So for one kind of mesh I have different current values.

Someone can help me if he have any idea.

Thank you very much


4 Replies Last Post May 15, 2019, 7:34 a.m. EDT
Edgar J. Kaiser Certified Consultant

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Posted: 5 years ago May 10, 2019, 7:49 a.m. EDT

Hi,

I would recommend to perform a mesh convergence study to find out what mesh resolution is needed for consistent results.

Cheers Edgar

-------------------
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Hi, I would recommend to perform a mesh convergence study to find out what mesh resolution is needed for consistent results. Cheers Edgar

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Posted: 5 years ago May 10, 2019, 8:13 a.m. EDT

I also recommend reading the Computing Accurate Fluxes section of the COMSOL reference manual it's a very interesting and useful read. You'll find the the reference manual at

/path/to/comsol/multiphysics/doc/pdf/COMSOL_multiphysics/

The file is

COMSOL_ReferenceManual.pdf
I also recommend reading the **Computing Accurate Fluxes** section of the COMSOL reference manual it's a very interesting and useful read. You'll find the the reference manual at /path/to/comsol/multiphysics/doc/pdf/COMSOL_multiphysics/ The file is COMSOL_ReferenceManual.pdf

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Posted: 5 years ago May 13, 2019, 3:48 a.m. EDT

Thank you Edgar and Alexis for recommandations. I do that and I keep you informed. Lyes

Thank you Edgar and Alexis for recommandations. I do that and I keep you informed. Lyes

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Posted: 5 years ago May 15, 2019, 7:34 a.m. EDT

Hello,

I tried reacf(V) on a known physic and I have the most accurate electrical current.

Thank you Alexis and Edgar Lyes

Hello, I tried reacf(V) on a known physic and I have the most accurate electrical current. Thank you Alexis and Edgar Lyes

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