[C-L]

hi all,

I am having some issues with snappyHexMesh crashing when creating large (100 M + cells) meshes and I am wondering if anyone recognises the problem. I have successfully generated a mesh of ~50M cells using SHM on 128, 256, 512 and 1024 processors (and subsequently run pimpleFoam) but for the larger mesh the solver crashes during the balancing (I think..?) stage - although there are no errors provided! I have provided the output log file below.

I think this is a memory issue, but I expected 1024 processors, each with 2GB RAM, to be more than adequate, especially since the 50M cell mesh generated fine on only 128 cores.

Does anyone have any suggestions as to what might be the issue / what else I could try to make it run?

I am using scotch decomposition and generating a simply cubic geometry with periodic BCs - the refinement is based on a refinement plane, but will use an STL file at a later date.

Thanks in advance!

PHP Code:


Edge intersection testing:
    Number of edges             : 130502260
    Number of edges to retest   : 96264640
    Number of intersected edges : 0
Refined mesh in = 7.5 s
After refinement shell refinement iteration 2 : cells:42925180  faces:130502260  points:44651900
Cells per refinement level:
    0   2131420
    1   1510880
    2   8201920
    3   31080960
Balanced mesh in = 316.99 s
After balancing shell refinement iteration 2 : cells:42925180  faces:130502260  points:44651900
Cells per refinement level:
    0   2131420
    1   1510880
    2   8201920
    3   31080960

Shell refinement iteration 3
----------------------------

Marked for refinement due to distance to explicit features : 0 cells.
Marked for refinement due to refinement shells             : 10360320 cells.
Determined cells to refine in = 1.98 s
Selected for internal refinement : 10360320 cells (out of 42925180)
Edge intersection testing:
    Number of edges             : 353249140
    Number of edges to retest   : 260734720
    Number of intersected edges : 0
Refined mesh in = 17.7 s
After refinement shell refinement iteration 3 : cells:115447420  faces:353249140  points:122354300
Cells per refinement level:
    0   2131420
    1   1510880
    2   8201920
    3   20720640
    4   82882560