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Any good ideas: point dipole on dielectric surface: Solver does not find a solution

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Hello all,
I am learning COMSOL 4.1 and I reached a point where I am stuck.

I am trying to model the following scene in a3D geometry with the COMSOL electrostatics package:

A sphere of dielectric material A is placed on a substrate. Inside the sphere I place an electric point dipole.
The substrate B is dielectric, too, and has a thin surface layer C with a different dielectric constant. On top of the surface, surrounding the sphere is air. The substrate has a imaginary component of the dielectric constant.

I have made the substrate approx. 100 times larger than the sphere to aprox. infinity. Ultimately, I want to integrate over E^2 (E=electric field) in the absorbing dielectric substrate), but first I need to find the potential.

Now my problem is that beside the initial values I cannot change any other properties of the Electrostatics parameters. The boundary conditions seem to be "locked". Charge conservation is applied to all domains and for the E field COMSOL uses the constitutive relation of the relative permittivity. Zero charge applies to all outer boundaries and I cannot change it.

As a result I do not know what to change or how to approach the problem when the solver fails. I tried changing the mesh size, but that did not help.

How would you proceed?

Many Thanks for any suggestions!

Best,
james

PS:
I have attached the COMSOL file in case you are interested.






1 Reply Last Post 14 juin 2011, 14:32 UTC−4

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Posted: 1 decade ago 14 juin 2011, 14:32 UTC−4
Hi All,

I am sure my problem is easy to fix for an experienced user.

How to set proper boundary conditions for the model?

Best,
james
Hi All, I am sure my problem is easy to fix for an experienced user. How to set proper boundary conditions for the model? Best, james

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