No energy conservation in interRegionHeatTransfer model
 

I recently gave the fvoptions for interRegion heat transfer a try and for some reason I seem to be unable to conserve energy. The example case in the tutorial contains a lot of fancy things but I tried to reduce the complexity.
- two identical meshes overlapping
- constant material properties
- laminar flow
- slip walls
I included my test-case in attachment. In this case I use a constant heat transfer coefficient and a constant area over volume. If I read the source code correctly it will add a source term to the energy equation that is the product of these constants with the cell volume and the temperature difference between the two regions. As the temperature difference will be positive or negative depending on the region so will the source term. As we have identical fluids and identical flow rates in my case you would expect the change in temperature to be identical. This is however not the case.

Is this a bug or am I missing something?

Tom

I found my error. The tutorial case contained some really tightly defined limiters on the density. If you turn of the limiters in both fvSolution files the results are ok.

Hello,
Sorry to open old post.
can anyone tell me why "constantHeatTransfer" or "inter-region heat transfer" fvOption is used for?
I tried to search it but I couldn't find the answer.
I can see that both the region are overlapping. is this the reason we are using inter-region heat transfer fvOptions?