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Electric filds

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Hi all.

I have two copper electrodes situated in dielectric box full of water.
I can measure resistance, current and electric fields in real box using different devices.

Now I what to simulate all that in COMSOL.
Using a "electric current' I create a box and electrodes, then connect one elctrode to terminal 1 with high potential (+30 V) and connect second electrode to terminal whit 0V.

What shall I do to know power consumption of that system in model.
What shall I do to know resistance of that system in model.
And what parameters I shall add to that system to simulate electric field in the earth reservoir with ground connection.

3 Replies Last Post 14 avr. 2012, 14:06 UTC−4

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Posted: 1 decade ago 4 avr. 2012, 13:47 UTC−4
Pavel,

You can plot the current through each electrode by using a 1D plot group (found in "Results")
Within this 1D plot group, you need to add a global variable plot.
This global variable plot will allow you to select the current through any given terminal. (You're looking for a small icon which is an orange and green triangle on top of one another.)

One you know the current you should know your resistance and power of the system. (R = V/I and P = V*I).

The last part of your question is a bit confusing, and I think you need to reword it to get what you're looking for. I'm not sure how to add in an external electric field. You may want to explore your options with the electrostatics module or the magnetic and electric field modules.

I also recommend walking yourself through one of the many tutorials with the AC/DC module. They are very basic and would help you figure out how to work with COMSOL to export the data you need regardless of what physics you are simulating.

Regards,
Azer
Pavel, You can plot the current through each electrode by using a 1D plot group (found in "Results") Within this 1D plot group, you need to add a global variable plot. This global variable plot will allow you to select the current through any given terminal. (You're looking for a small icon which is an orange and green triangle on top of one another.) One you know the current you should know your resistance and power of the system. (R = V/I and P = V*I). The last part of your question is a bit confusing, and I think you need to reword it to get what you're looking for. I'm not sure how to add in an external electric field. You may want to explore your options with the electrostatics module or the magnetic and electric field modules. I also recommend walking yourself through one of the many tutorials with the AC/DC module. They are very basic and would help you figure out how to work with COMSOL to export the data you need regardless of what physics you are simulating. Regards, Azer

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Posted: 1 decade ago 9 avr. 2012, 07:57 UTC−4
Thank you very much for you answer. I'll try your advices.

About the last part of my question, I mean Shall I connect bottom and sides of tank to ground, if I want simulate electric field between two electrodes in the pond.

Also Can you tell me difference between "ground" and "terminal" in Comsol?

Is it correct using "electric current" or better using "electrostatic" If I want know only electric fild (norm) in water?
Because sometimes I have differences in results.
Thank you very much for you answer. I'll try your advices. About the last part of my question, I mean Shall I connect bottom and sides of tank to ground, if I want simulate electric field between two electrodes in the pond. Also Can you tell me difference between "ground" and "terminal" in Comsol? Is it correct using "electric current" or better using "electrostatic" If I want know only electric fild (norm) in water? Because sometimes I have differences in results.

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Posted: 1 decade ago 14 avr. 2012, 14:06 UTC−4
Hi all


Now I am trying to model a rotating machinery in AC/DC Module. It is exactly an axial flux permanent magnet synchronous generator.
I`ve finished the geometry and model of the generator. Yes, It`s like a disc, so it will be more efficient than the radial one.

These are the explanation of my model:
- Permanent magnet poles are pleced in the back yoke of rotor.
- Stator, which consist of some winding/coil, are placed between the two rotor. I`m using coreless stator one.
- There is air gap between rotor and stator.

I have adjusted the subdomain physics settings by choosing the material and the H-B equation, but I have no idea, what I have to do next.. So users, please suggest me what I have to adjust next.

- How to adjust the boundary settings?
- What function and equation that I`ve to give for the model.. In what part?
- and how to visualize the outcoming voltage of every phase of the generator??


Thank you
Halim, Zahari
Hi all Now I am trying to model a rotating machinery in AC/DC Module. It is exactly an axial flux permanent magnet synchronous generator. I`ve finished the geometry and model of the generator. Yes, It`s like a disc, so it will be more efficient than the radial one. These are the explanation of my model: - Permanent magnet poles are pleced in the back yoke of rotor. - Stator, which consist of some winding/coil, are placed between the two rotor. I`m using coreless stator one. - There is air gap between rotor and stator. I have adjusted the subdomain physics settings by choosing the material and the H-B equation, but I have no idea, what I have to do next.. So users, please suggest me what I have to adjust next. - How to adjust the boundary settings? - What function and equation that I`ve to give for the model.. In what part? - and how to visualize the outcoming voltage of every phase of the generator?? Thank you Halim, Zahari

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