G'day,

We are running a number of external flow scenarios and continue having issues with the flow results near the boundaries of the computational domain.

Our system is fairly simple, we are trying to analyse subsea flow over a simplified seabed and around block shaped objects.

We can't understand why the velocity is speeding up near the domain edges (see attached picture).

Our input velocity is in the X-Direction and no matter what velocity we have the same problem.

Any help on this matter would be much appreciated.

Thank you!

We solved their problem offline... here is the resolution.

Joel,

I think that the manual pressure dependency (151 kPa to 101 kPa from 0 m at sea floor to 4.5 m at top of sea) for ambient that you defined makes the difference. I set it as a pressure potential and put the pressure that is at the origin (see picture); it figures out the pressure at the top for you after running a few iterations. Now it only gets to 110 kPa (instead of 101 kPa) but that could possibly be caused by your own calcs for pressure at the sea floor accounts for sea water with salinity, thus here you might need to define a new water fluid with different density to account for the difference.