3D-1D coupling
 

Hi everyone,

I would like to couple a bunch 1D domains at each and every point of a 3D domain boundary (2D surface). See the attached .jpg to understand.

Here is what I tried until in Comsol in a simple conduction problem :

1. I work in 3D.
2. I draw 2 adjacent 3D cubes.
3. I set the boundary conditions, etc.
4. For my 1D domain (1D in theory, drawn in 3D), I do this:
In Physics\Equation System\Subdomain Settings\keep only the terms for 1 coordinate (the one normal to the boundary) in the Weak equations and the Variables equations.

I want to solve this sequence where both domains interact with each other :
- solve 3D domain
- solve 1D domain with boundary values of solved 3D domain
- solve 3d domain with new boundary values from 1D domain
- and so on

It solves quickly, no error messages, but I have to validate my solution. It looks a little weird to me since 1D nodes should be aligned, and here I still have tetrahedrons with unaligned nodes...

I can't find nothing related to my problem in the Comsol integration-extrusion-projection coupling variables theory. Can we do that in Fluent?

Thanks,
François