convergence problem for opening BC (entrainment)
 

Hello everyone!

I'm having convergence problem using opening BC with static pressure (entrainment) condition. My other BCs are inlet and outlet. My model is two-phase compressible. I've played around the automatic timescale and local timescale but I still have poor convergence. If I use inlet instead of opening-entrainment, my simulation converges. Do you have any suggestion guys? Entrainment BC is more suitable for my model. Thanks a lot!

The entrainment BC is much harder to converge so if you are having problems converging then I would not use it. It might be better to move your boundary further away so you can use the simpler non-entrainment boundaries.

Thanks a lot for the advice Sir Glenn! Do you think entrainment BC is more mesh sensitive than other BC? Thanks.

It probably is. It is certainly harder to converge in general than the normal BCs. That is why if possible I prefer to move the boundaries further away from the region of interest and use simpler BCs instead.

I got it sir. Thank you so much again!