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which study is applicable if AC current is used in the geometry.

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Hello, I am solving a problem of 2D geometry using comsol for impedance measurement. I have inserted 16 arcs equidistantly placed forming a circular geometry. I need to find the voltage values by giving an AC current of 1mA with 50 Hz frequency to two arcs and measure the voltage at all other arcs successively. Then again move the current to next two arcs and measure the voltage at all other arcs. This procedure is continued till all the arcs are given the ac current and voltage is measured. The AC current is given through arc 0 and 1 and the potential voltages are measured across the other 13 arc pairs 2-3, 3-4, . . . and 14-15. This is first projection. In the second projection current is injected through arc1 and arc2 and the voltages are measured across the other 13 arc pairs 3-4, 4-5, . . . And 15-0. And so on. Like this total 16 projections and 13 readings in each projection. I have to tabulate (and plot) these readings in a file for further processing. Which study I should use? Frequency domain, Stationary or Time Dependant study? (Since AC current is given) Since current is applied subsequently to all the arcs and voltage is measured in each projection. Do I need to change the position of input current source to the arcs manually in each projection? If it is possible to generate all the voltage value table of 16 projections and 13 readings by computing the study once, then how it is done? Please do the needful. Thanks.


3 Replies Last Post Jan 19, 2021, 8:58 PM EST
Robert Koslover Antennas, Waveguides, Electromagnetics

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Posted: 8 months ago Jan 18, 2021, 3:07 PM EST
  1. Is this by some chance a school homework or school lab class problem?
  2. You say "by giving an AC current of 1mA with 50 Hz frequency to two arcs". Do you intend to do this by applying some kind of source? Perhaps you could provide a picture/description of how you intend to connect that. (Hint: It could make a difference.)
  3. A closed loop carrying a time-varying current does not even have a strictly-defined potential (aka, voltage) at any particular point on it. Potential differences measured between two points on such a loop may depend on how you lay out the wires to your volt meter (in regard to how much of the magnetic flux from the loop that these wires intercept).
  4. See also https://en.wikipedia.org/wiki/Kirchhoff's_circuit_laws .
1. Is this by some chance a school homework or school lab class problem? 2. You say "by giving an AC current of 1mA with 50 Hz frequency to two arcs". Do you intend to do this by applying some kind of source? Perhaps you could provide a picture/description of how you intend to connect that. (Hint: It could make a difference.) 3. A closed loop carrying a time-varying current does not even have a strictly-defined potential (aka, voltage) at any particular point on it. Potential differences measured between two points on such a loop may depend on how you lay out the wires to your volt meter (in regard to how much of the magnetic flux from the loop that these wires intercept). 4. See also https://en.wikipedia.org/wiki/Kirchhoff's_circuit_laws .

Robert Koslover Antennas, Waveguides, Electromagnetics

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Posted: 8 months ago Jan 19, 2021, 1:23 PM EST

I received the information you sent me privately, which leads to a somewhat different view than I concluded from your initial description. Anyway, I think you should apply a frequency-domain stationary-type solution model, not a time domain model. If you want to automate the setting/execution of the voltage readings and current excitation, I suspect you will have to program that process using something like a MatLab script. Others here can probably offer much better advice about that, and the alternatives to doing that, than I can.

I received the information you sent me privately, which leads to a somewhat different view than I concluded from your initial description. Anyway, I think you should apply a frequency-domain stationary-type solution model, not a time domain model. If you want to *automate* the setting/execution of the voltage readings and current excitation, I suspect you will have to program that process using something like a MatLab script. Others here can probably offer much better advice about that, and the alternatives to doing that, than I can.

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Posted: 8 months ago Jan 19, 2021, 8:58 PM EST

Thank you for the prompt response.

Thank you for the prompt response.

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