Interface type frozen in CHT

Dear SimScale crew. I have been constantly experiencing issues with the “interface type” selector in CHT.

When I create a new simulation with an imprinted geometry the contacts are detected and I can usually modify the interface type. However, if I duplicate the simulation and bring a new geometry (imprinted), the interface type freezes. I had to create a new simulation and reconfigure everything. Then, the option was available again. I did not configure the contacts right away but went to set the boundary conditions first. Then I came back to the contacts and were frozen again. I supposed the boundary conditions setup might have interfered with the contacts, therefore I cancelled all assignments and still frozen “interface type”. In the end, this requires investing a lot of time reconfiguring a simulation from scratch over again to make unfreeze the contact type selection.

Is this a bug or I am missing something?

Best regards,


Hey there, and thanks for using the forum and taking the time to report this!

When you switched geometries on the copy of the simulation, were the contacts recomputed? Was it successful?

Could you also please share the link to your simulation so we can have a closer look to the case?

Dear @ggiraldof I have switched from many geometries and the contacts always seem to be recomputed, but the selection is frozen. As I mentioned, if I create a new simulation for “that” geometry, the contact selection type becomes available once again.

Let me see if I can explain it better:

After doing imprint, and creating a new simulation, you can select the contact type, no problem.

When I duplicate the simulation case with another geometry (the same with one part less), the contact type selection dialog is blocked.

So I have to create a new simulation from 0 and reconfigure everything. In this way the contact type dialog is unlocked again.

But I noticed that if I first configure the boundary conditions / materials in this new simulation the contact type dialog is blocked again. As far as I see hierarchially it is mandatory to configure the contact types first. It doesn’t matter if I unassign the boundary conditions and the contact type dialog.

It kind of “makes sense” as I suppose once you assign BC conditions, the algorithm also sets some part to part BC values (contacts) and then the selection becomes blocked.

I am afraid I cannot share the project as it is private. @paresh has access to itthough


Many thanks for reporting this.

I will try to reproduce the issue and forward it to our dev team in case it looks like a bug.

Dear @ggiraldof , I have reproduced the issue. The contacts type selector becomes locked when you click on “radiation on”. So I suppose the individual contacts have to be set with “radiation off” and then when you activate the radiation again they keep the assigned configuration, right?