[kola77]

Hello everybody,
I am trying to conduct a simulation of a simple shell-tube heat exchanger, but as soon as I start the run the solver crashes with an error with the following explanation:

If the isolated regions do not have the pressure level set either by the boundary conditions or using a reference pressure equation, you may encounter severe robustness problems.

This situation may have arisen because a domain interface was not properly defined during problem setup. Please carefully check the setup.

The solver will stop now and write a results file. The isolated regions can be visualised in CFX Post by making plots of the variable "Isolated Volumes".

If you are sure that the pressure level is set in each isolated fluid region then you can force the solver to turn off this check by setting the expert parameter "check isolated regions = f".

+--------------------------------------------------------------------+ | An error has occurred in cfx5solve: | | | | The ANSYS CFX solver exited with return code 1. | +--------------------------------------------------------------------+

End of solution stage.

I know this usually has something to do with problems of the geometry/mesh, but I couldn't find any noticeable glitches in mine. There were also no unconnected regions, the the interfaces seem to be correct. Nevertheless, what I have tried is the following:

• I have carefully and several times reviewed my setup
• I have redesigned my model from scratch
• I have refined the mesh
• I have tried to simulate a single pipe inside of a shell

All of the above ended with the same error, yet when I start an old file of another heat exchanger I have simulated a while ago it works fine. I have carefully examined my setup of that one and I can't fine any differences in the setup. If anybody has ANY idea what might be causing this I would be the happiest man on earth, since I am slowly getting desperate.

Is it possible that my installation of ANSYS is damaged in some way?

Thank you in advance for any potential help!