Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Boundary Conditions for imported mesh of human head

Please login with a confirmed email address before reporting spam

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 Mar 12, 2024, 2:39 p.m. EDT
Edgar J. Kaiser Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 8 months ago Mar 12, 2024, 6:18 a.m. EDT

Impossible to give any advice without seeing the models.

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

Please login with a confirmed email address before reporting spam

Posted: 8 months ago Mar 12, 2024, 2:39 p.m. EDT
Updated: 8 months ago Mar 12, 2024, 2:39 p.m. EDT

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.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.