I have some issius with boundary conditions. For a conjugate heat transfer simulation with joule heating following two issius:
If I creat a flow region around my cupper busbar and define the wall conditions to each end of the bar to get a voltage and a current, there a two values assigend for this boundary (air/cupper and wall). The program tells me that just one condition can be assigend.
My solution is to simply put holes in the flowregion or don’t cover the ends of the bar with air. This way I get the wallcondition to the busbar and it works with it but it’s not a good solution.
Is it possible to have complete with flowregion covered busbar and still assigne wall conditions for a current?
With CHT studies, whenever you have a contact between two volumes (i.e. pairs of faces from different volumes that touch each other), the contacts fully constrain the two faces.
Therefore, attempting to assign a boundary condition to contact faces causes them to get overconstrained, since you are constraining the faces in two different ways at the same time.
If the objective is to assign current in/out conditions to busbars, the options are:
Creating a small void in front of the busbar in/out faces, so that a contact is not generated (which allows for a boundary condition definition). From your description, this is what you are currently doing
Or you can extend the busbar in/out faces until the end of the flow region, so that the flow region doesn’t cover the current in/out faces
