Hello,

I'm trying to simulate a geometry that's periodic in not one, but two directions. I'm using the transient thermal module. As a minimal example, let's look at this 10 mm cube:

I want all the heat flux that goes out of one side go into the opposite side, as if the cubes were arranged in an infinite XZ grid.

As you can see, I have applied linear periodic BCs in the X and Z directions, each for the corresponding pair of opposing faces. I have chosen the "high" regions so that they have the larger X or Z value. The "linear shift" is equal to 10 mm.

However, when I generate the mesh, I get this error message:

"The mesh could not be generated because two faces adjacent to an edge have different match controls applied to them. To correct this, ensure that match control settings are the same for both adjacent faces."

Next thing i tried is to set up Match controls for each pair of adjacent faces like this:

Which returns the error message

The meshing algorithm cannot find matching topology. Please verify the topology and the position as well as the orientation of any associated coordinate systems.

Can anyone help me with this? I'm sure it can be done, but I cannot figure it out! Thanks for reading.