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Terminal Boundary Condition

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Hi everyone,

I'm currently trying to model a capacitor and am having difficulty introducing a voltage to the system. In the picture shared, the upper and lower plates were assigned the aluminum material and the middle plate is assigned acrylic plastic to represent a dialectric.

I've seen other threads before discussing the "terminal" boundary condition, which supposedly simulates a terminal hooked up to an outside circuit that can simulate electron flow and induce a voltage drop or some sort of capacitance across the model. The only issue is that the "terminal" condition simply refuses to show up in my COMSOL. I can't find it anywhere - in the AC/DC module, in the help bar, basically it seems that it doesn't exist on my computer. Has anyone else run into a similar problem? Are there other ways to achieve this capacitor simulation I'm going after that don't involve terminal?

Thanks so much! !



2 Replies Last Post 26.11.2020, 12:14 GMT-5
Jeff Hiller COMSOL Employee

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Posted: 4 years ago 25.11.2020, 13:57 GMT-5

Hello Kendall,

The most likely explanation is that the license you are using does not include the AC/DC Module, Plasma Module, MEMS Module or Semiconductor Module (Those four optional add-on products are the ones that include the Terminal condition). Note that a folder marked "AC/DC" will appear in the Model Wizard whether or not your license includes the AC/DC Module; this is because there are capabilities in the field of AC/DC modeling that are included in the core COMSOL Multiphysics. To determine if your license does in fact include one of those modules, you need to go to File > Licensed and Used Products.

Best regards,

Jeff

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Jeff Hiller
Hello Kendall, The most likely explanation is that the license you are using does not include the AC/DC Module, Plasma Module, MEMS Module or Semiconductor Module (Those four optional add-on products are the ones that include the Terminal condition). Note that a folder marked "AC/DC" will appear in the Model Wizard whether or not your license includes the AC/DC Module; this is because there are capabilities in the field of AC/DC modeling that are included in the core COMSOL Multiphysics. To determine if your license does in fact include one of those modules, you need to go to File > Licensed and Used Products. Best regards, Jeff

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Posted: 4 years ago 26.11.2020, 12:14 GMT-5

Capacitance calculations can often be performed using the Potential boundary condition, and integrating the normal electric displacement vector to find the electrode charge.

Capacitance calculations can often be performed using the Potential boundary condition, and integrating the normal electric displacement vector to find the electrode charge.

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