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direction of current density
Posted 2013/10/16 23:41 GMT-4 Low-Frequency Electromagnetics Version 4.3a 1 Reply
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Hello,
I have a problem when I want to calculate the amount of current through surface current density. To investigate the amount of current delivered through an electrode I simulated a simple model.
The model consists of three cubes with unit dimension connected to each other. The center cube has these electrical properties:
Conductivity: 233260e-6
Relative permittivity: 17.719000e6
And the other two cubes have the following properties:
Conductivity: 1.45e6
Relative permittivity: 1
Imagine a semi-conductor material between two electrodes. Terminal was set to be equal to I_0=wv1(t[1/s]) in which wv1 is a square waveform with angular frequency equal to 314.15 rad/sec and amplitude equal to 5.
As you can see in the attached figure, there are negative current densities for the surface shown in the figure. How can we interpret such a negative current densities? How can we calculate current flowing through electrode having current density?
Kind regards,
I have a problem when I want to calculate the amount of current through surface current density. To investigate the amount of current delivered through an electrode I simulated a simple model.
The model consists of three cubes with unit dimension connected to each other. The center cube has these electrical properties:
Conductivity: 233260e-6
Relative permittivity: 17.719000e6
And the other two cubes have the following properties:
Conductivity: 1.45e6
Relative permittivity: 1
Imagine a semi-conductor material between two electrodes. Terminal was set to be equal to I_0=wv1(t[1/s]) in which wv1 is a square waveform with angular frequency equal to 314.15 rad/sec and amplitude equal to 5.
As you can see in the attached figure, there are negative current densities for the surface shown in the figure. How can we interpret such a negative current densities? How can we calculate current flowing through electrode having current density?
Kind regards,
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1 Reply Last Post 2013/10/17 4:39 GMT-4
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Posted:
1 decade ago
Current is calculated as the scalar product of the current vector and the surface normal. If they are in opposite directions, current density is negative. Hence, do not bother the sign.
Lasse
Lasse