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Surface Charge on Copper Boundary Pyramid

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Hello,

I'm new to comsol and I'm trying to get comsol to plot the potential and the electric field of a copper boundary pyramid. I keep getting the same error over and over again. Also, how do I calculate and view the far electric field away from the pyramid? The error is in the attachment along with the model. I'm using the electrostatics interface. Help very much appreciated.

Eugene Harris

2 Replies Last Post 22 mar 2011, 08:11 GMT-4

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Posted: 1 decade ago 8 mar 2011, 21:43 GMT-5
These are the attachments that I said were attached. For some reason, they weren't attached.
These are the attachments that I said were attached. For some reason, they weren't attached.


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Posted: 1 decade ago 22 mar 2011, 08:11 GMT-4

Hello,

I'm new to comsol and I'm trying to get comsol to plot the potential and the electric field of a copper boundary pyramid. I keep getting the same error over and over again. Also, how do I calculate and view the far electric field away from the pyramid? The error is in the attachment along with the model. I'm using the electrostatics interface. Help very much appreciated.

Eugene Harris


Hi Eugene,

the problem is, that it's unclear what you want to solve for. You have set a starting potential of 0 over the entire domain, and you have applied a certain surface charge density on the faces. Now you have to realize that you have made a solid copper pyramid, and really there can be no voltage gradient (electric field) within a copper domain in such a static situation, since the electrons within the metal will rearrange to counter this internal field.

Also, you need some positive charges and some negative charges in your model to create an electric field, since field lines flow from positive charges to a negative ones. And to calculate the electric field in air, you must make actual air domains.

I have added a model, where I applied a positive charge density on two faces, and a negative one on two opposite faces, and changed the domain to air. hope this helps.
[QUOTE] Hello, I'm new to comsol and I'm trying to get comsol to plot the potential and the electric field of a copper boundary pyramid. I keep getting the same error over and over again. Also, how do I calculate and view the far electric field away from the pyramid? The error is in the attachment along with the model. I'm using the electrostatics interface. Help very much appreciated. Eugene Harris [/QUOTE] Hi Eugene, the problem is, that it's unclear what you want to solve for. You have set a starting potential of 0 over the entire domain, and you have applied a certain surface charge density on the faces. Now you have to realize that you have made a solid copper pyramid, and really there can be no voltage gradient (electric field) within a copper domain in such a static situation, since the electrons within the metal will rearrange to counter this internal field. Also, you need some positive charges and some negative charges in your model to create an electric field, since field lines flow from positive charges to a negative ones. And to calculate the electric field in air, you must make actual air domains. I have added a model, where I applied a positive charge density on two faces, and a negative one on two opposite faces, and changed the domain to air. hope this helps.

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