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Boundary Conditions for imported mesh of human head

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I am working on modeling the interaction of microwave plane wave pulses (1 GHz) with spherical geometries simulating a human head. Using the RF module, we built a layered spherical model, and after some iterations, were able to successfully get an electric field distribution for multiple lossy dielectric layers. Next, instead of building the geometry in COMSOL, we imported a mesh based on a segmented MRI image. After remeshing, we were able to get the model to run; however, COMSOL appears to default to assuming perfect conductors in the outer materials (skin, then bone) and not following the over-ride of the perfect conductor with the dielectric properties for the layers. We are using an impedance boundary condition. Why is the model continuing to treat the boundaries as perfect conductors? We are losing all of the field at the surface. In the spherical model, we used the same materials, same parameters, etc. The only difference is we went to an imported geometry. What are we missing??


2 Replies Last Post 12 mars 2024, 14:39 UTC−4
Edgar J. Kaiser Certified Consultant

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Posted: 8 months ago 12 mars 2024, 06:18 UTC−4

Impossible to give any advice without seeing the models.

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Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Impossible to give any advice without seeing the models.

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Posted: 8 months ago 12 mars 2024, 14:39 UTC−4
Updated: 8 months ago 12 mars 2024, 14:39 UTC−4

A guess is that your imported geometry contains some voids. Comsol would assign the surfaces of the voids as perfect conductor.

A guess is that your imported geometry contains some voids. Comsol would assign the surfaces of the voids as perfect conductor.

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