You have quite few number of advanced concepts, which makes it difficult to obtain the issue.
I would recommend starting simple. Letβs add only one of the advanced concepts first, then run the simulation. If successful, you can carry on adding the second advanced concept. This will make it easier to determine the advanced concept associated with the issue.
In case itβs mesh related or to understand if itβs mesh related, you can use the following knowledge base article to solve the mesh quality problem in your domain.
I would recommend checking the velocity inlet value 1800m3/s is way too high for the inlet total area. It seems that your 210 inlets have each an area of 0.0415m2, so the inlet total area is is about 8m2 which means that the require velocity to fulfill that requirement is about 200m/s. I donβt think an incompressible buoyant heat transfer solver is able to handle that. And as @kaany said, if we add a huge amount of sources the simulation will not succeed.