What's the parameters of the material 'pec'?

[Wz]

Hi 

I want to know what the parameters of the material 'pec' are, such as the relative permittivity, the conductivity and so on .And is anyone know  what parameter will change when the metal is corroded. Will the relative permittivity bigger or smaller?

[Antonis Giannopoulos]

PEC means "Perfect Electric Conductor" It is not a real material but one that one that assumes that electrical conductivity is infinite. Its presence is enforced by setting the Electric Field to zero. So, in essence is applied as a boundary condition. It is used to mimic the behaviour of metals for frequencies where the skin depth is extremely small and irrelevant. There are no real electrical properties associated with PEC. 

There are papers in the literature that describe the effects of corrosion products on the electrical properties use a simple Google search and you will find a lot of information.

Antonis

[Wz]

Thank you.

I have another question. The input file is posted. The difference between the material of 'soil' and 'metal' is the relative permittivity,  But why are there two similar part in the picture....

#material: 2 0.01 1.0 0.0 soil

#material: 10 0.01 1.0 0.0 metal

--------------------------------------

#domain: 1.5 0.8 0.75

#dx_dy_dz: 0.01 0.01 0.01

#time_window: 10e-9

-------------------------------------

#box: 0.0 0.0 0.0 1.5 0.8 0.6 soil

#cylinder: 0.3 0.4 0.3 0.7 0.4 0.3 0.1 metal

#cylinder: 0.9 0.2 0.3 0.9 0.6 0.3 0.1 metal

--------------------------------------------

#waveform: ricker 1.0 900e6 MySource

#hertzian_dipole: y 0.2 0.4 0.65 MySource

#rx: 0.3 0.4 0.65

#src_steps: 0.02 0.0 0.0

#rx_steps: 0.02 0.0 0.0

[Craig Warren]

You have defined 'metal' to be a dielectric with a relative permittivity of 10 and conductivity of 10mS/m, which is a bit confusing. Your model also potentially suffers from numerical dispersion, see the warning message in red when you run the model. Antonis, suggested some material you can read to understand numerical dispersion and how to mitigate it.

Kind regards,

Craig

[Wz]

I can reduce the numerical dispersion now. The warning message in red can be in white. Maybe the threshold of the numerical dispersion is 2 percent. But I don't understand what you said about the material 'metal'. What's the relationship between the relative permittivity and the conductivity?

Best wishes

Wz

[Craig Warren]

I was suggesting you might want to rename your material 'metal', as it currently does not have the properties of a metal, rather a lossy dielectric.

Kind regards,

Craig