I'm simulating a shell and tube heat exchanger in comsol .
I am plugging some of the tubes within the structure to see its effect on del.P and temperature.
When I plug 18 of 19 tubes, and one tube remains open at the top, it gets simulated. But, when this open tube is at the bottom, the simulation doesn't get converged.
I think the boundary conditions are correct, as other cases are getting simulated.
Please also see the attached case.
The study is stationary