TIME STEPPING / CONVERGENCE ISSUE with a SEVERAL HOURS lasting 2-phase simulation + ERROR MESSAGE
I am having severe problems with convergence and my time stepping settings (under "run simulation").
I am doing a transient VOF 2-phase simulation (phase1=nitrogen, phase2=liquid). The special thing about my simulation is that I have a filling process (liquid enters through inlet into tank with v=0.1m/s) in the beginning for a few seconds (e.g. 10) and then the liquid enters through an interface into a porous zone where it gets soaked, which takes 2-3 hours. The porous zone and the tank are initially completely filled with nitrogen at p=40mbar.
In the following, you can see my case scheme with its BCs:
For the inlet to close after some seconds (e.g. 10s) I set up an Event to change the BC type from velocity-inlet to wall.
At first, I tried to go with fixed time steps, but I think this can't work out since it would take far too much time with such small time steps (e.g. 0.0001s) to ideally represent several hours (2-3h) in reality.
Recently, I set up the adaptive time-stepping method like so:
The simulation took about 12 hours but then suddenly stopped (I don't know why???) and showed this:
"Error: Floating point exception."
For the residuals, I set all the absolute criteria to 1e-06.
Following attached the convergence after some time and when I recently checked it.
Subsequently, I wanted to open Post, but it was empty (not showing my geometry/mesh). What could be the reason?
When I wanted to open Solutions I got this error message (see attached):
Anyone had these issues before?
Attached there is also:
- a screenshot of the geometry/mesh &
- the output of the console box.
Maybe someone has an idea why the simulation never converges having a look at the console messages?
I would really appreciate any type of help since this is part of my master thesis and I have still a lot of work to do!