Hi Kim,
in order to increase the quality of your mesh please try to remove most of the small feature details in your projects such as these two examples.
Example one, thin edge on the end of the pipe, here actually the divergency occurred.
Thin gap within the flow region, and small features.
Please try to start with a model which has only large features, you can later on add feature ins order to see the accuracy of your simulation.
Also you won’t need the perforated geometry, as this will be represented by the defined prouse media.
Here you also only need to assign the geometry primitve, so you can deselect the assigned volume.
Last, i guess you missed the assignment of the symmetry plane to the cutted part.
Please assign a symmetry boundary condition here:
Best regards
Sebastian