[sroy]

I am running a test pump station model, which crashes after running for a while. I have used volume flow rate both in the inlets and outlets. I tried using different mesh refinements and smaller time steps but couldn't figure out how to fix the problem. I am also attaching the checkMesh.out along with the model files. I have just found "If you specify velocity/flow rate at the inlet/outlet, you should specify pressure at the outlet/inlet." Is it possible to use pressure in the inlet and flow at the outlet? I highly appreciate your help.

You will find the model files at: https://dsllctn-my.sharepoint.com/:u...PguLA?e=IKxTqi

I have ran another model of the same pump intake station where I used pressureInletOutletVelocity for the inlets and flowRateOutletVelocity for the outlets. This model also crashed after running 17s with similar error message. Here is the link of the model files: https://dsllctn-my.sharepoint.com/:u...OZXRQfoCvznmDw

I highly appreciate with any insight. Thanks.

[Tobi]

Hi,

Using velocity definitions for both, inlet and outlet, is not a good choice as you don't give any degree of freedom to the system. Consequently, I would expect a crash.

Commonly, we use fixed velo at the inlet and fixed pressure at the outlet (or vice versa) for incompressible solvers. Potentially, I would use the Mass flux or volumetric flux at the outlets (if known) and fixed pressure value at the inlet. Another way, if you know it, would be to set up a pressure driven case. Therefore y fixed pressure outlet and totalPressure inlet conditions while keeping the velocity conditions free. E.g. zeroGradient at the outlet (or inletOutlet to prohibit potential reverse flows) combined with a pressureInletVelocity at the inlet.

However, if your case runs for quite a while, you should analyse the flow date quite close to the crash. E.g. the last few time steps (and maybe some intermediate steps during your run). Use paraview for that to get a feeling where and potentially why your case crash.

Good luck