Butterfly open foam terminating in the middle of simulation

I am studying the heat transfer inside a building creating a virtual wind tunnel using boundary components to specify temperature and wind speed. I set the run to 2500 iterations but it stops at 220 giving up an error message. I am attaching the gh file with error msg. Please anyone can review my process.

FINALTCS.gh (644.6 KB)
26janTCSfinal.3dm (774.5 KB)

Simulation diverged (you can tell by the residuals having quadrillion billion values). This has nothing to do with BF and is OF specific.

It’s really hard to tell why this happens, so case specific. The only universal reason for it across cases is mesh quality. Remesh with better quality and try again.

Kind regards,

@TheodorosGalanos thanks for your input. I tried to increase the cell block mesh but snappy hex mesh fails giving a message of virtual memory fail exceeds. I am not able to go through it.
And is the process ok creating a tunnel from boundary conditions and temperature.
I will be thankful if u help me in understanding the fundamentals of this.