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Electric current (ec) and Electrostatic (es) module
Posted 03.06.2024, 05:34 GMT-4 2 Replies
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I have a question regarding the differences between the Electric Current (ec) and Electrostatic (es) modules in COMSOL software. Specifically, I want to perform simulations to analyze potential, current density, and related parameters.
In the Electrostatic (es) module, I know that only the relative permittivity parameter is used for calculations, employing Poisson's and Laplace's equations. However, in the Electric Current (ec) module, both electrical conductivity and relative permittivity are used. When analyzing potential distribution, I observed that changing the conductivity value affects the potential distribution, while changing the relative permittivity does not.
The attached image shows my model, which consists of two cathode poles surrounded by a wall. When I alter the electrical conductivity of the wall, the potential distribution changes accordingly.
I am curious whether using the Electric Current (ec) module to analyze potential is accurate in COMSOL software. And does electrical conductivity affect the potential calculation formula?. If there is an impact, what formula should be used to analyze it?
Thank you for any advice
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Hi,
This section on Charge Relaxation Theory in the AC/DC Module User's Guide covers when and why to use the Electric Currents and Electrostatics interfaces: https://doc.comsol.com/6.2/docserver/#!/com.comsol.help.acdc/acdc_ug_theory.05.31.html
If you are simulating what essentially is DC current conduction, i.e. the charge relaxtion time being much smaller than the time scale of your experiment/device, then the electric potential and field distributions are indeed goverened by the electrical conductivity. However, note that the Electrostatics equation is still consistent with the your potential distribution as space charge and/or surface charge accumulates accordingly if there is a gradual or sudden spatial change in the charge relaxation time.
Best regards,
-------------------Magnus
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am studying the in fluence of suspended metallic dust particles in mineral oil under positive lightning impulse voltage . A cylidrical 1 litre point - plane test cell with a gap distance of 60 mm will be filled with mineral oil ( with and without contamination). The objective of the research is to determine the influence of suspended metallic dust particles on streamer velocity. A model has to be developed and simulation results have to be compared with experimental set results. How do l implement it using electrostatics and the transport of diluted species physics.
Your help is appreciated. I have been struggling for the past 6 month.
Regards
Amos
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