[Noix_V]

Hello everyone.


I'm trying to model a charging gas tank: a cylindrical canister that starts on let's say, 1 bar of pressure and has only a single inlet with a pressure-inlet condition of 8 bar. For now, it doesn't really matter what gas it is.

That problem sounds extremely simple, but I'm facing heavy troubles with just making that work.

All I have is a 3D cylinder (it needs to be modelled as 3D) with another smaller cylinder connected to it as to simulate a gas line. I'm using an ideal-gas density model for my material (air), and no matter what starting conditions I put in initialization the problem quickly diverges with the folllowing errors:

# Divergence detected in AMG solver: Coupled -> Decreasing coarsening group size! # Divergence detected in AMG solver: Coupled -> Increasing relaxation sweeps!
# You may try the enhanced divergence recovery with (rpsetvar 'amg/protective-enhanced? #t)

I've attached some screenshots of my current attempt.


I'm really out of ideas at this point. I tried refining the mesh to no avail. I'm pretty sure the problem has to be something with the geometry or my initialization. Any suggestions?

Thanks for your time.

[Noix_V]

Update: I think it has something to do with either my mesh or my problem initilization. I ran other geometries and they are just fine. Or maybe my dimentions are too small?