[Springroove]

Hi all,

I am working on a problem comprising a train travelling in an evacuated tube at 300 m/s (M=0.88). However, it takes about 30+ hours to reach about 10,000 iterations which is not even convergence. Does this maybe have to do with my boundary conditions? (I only have 300k nodes and the full domain is 200m x 0.1m)
I've tried different bc's but to no avail. For the latest run I have the following bc's:

Inlet velocity u = 300 m/s and total temperature of 300K
top, bottom and side walls all moving with 300 m/s in x-(flow)-direction
outlet pressure of 100 Pa (which is the ambient tube pressure)
the train is just a no-slip wall

I'm using the SST model
I don't think it's due to my workstation as I am using a laptop which has i7 @2.2 GHz with 16GB RAM.

Cheers!!

[litzj]

I do not know Mach # of this case, but it seems that compressibility should be considered...

If you do not correctly mesh for near-shock region, vibrated shock position interrupt your convergence.

[Springroove]

Thank you for your answer.

Do you maybe know some tutorials or examples where I can find things related to these boundary conditions?

I was wondering whether it might be due to the imposed velocities and the outlet pressure.

Cheers