code_saturne User's Forum

Hi all,
i'm sorry to post something regarding Syrthes in the code_saturne forum but i can't post anything in the EDF forum where i found this error:

https://code-saturne.info/products/code ... /851877331

i've encountered the same error but with a 6000 faces radiation mesh, and i can't get any coarser with the mesh.

*** CFDF3D : calcul des facteurs de forme
10.00 % du calcul effectue
20.00 % du calcul effectue
30.00 % du calcul effectue
40.00 % du calcul effectue
50.00 % du calcul effectue
60.00 % du calcul effectue
70.00 % du calcul effectue
80.00 % du calcul effectue
90.00 % du calcul effectue

*** SMOOGC: SMOOTHING PAR GRADIENT CONJUGUE
ITERATIONS PRECISION RELATIVE PRECISION ABSOLUE
SMOOGC 69 ITERATIONS PRECISION RELATIVE = 0.81172E-02 PRECISION ABSOLUE = 0.76339E-10
At line 565 of file /build/buildd/syrthes-3.4.2-dfsg1/src/s/inisol.F (unit = 65, file = '/home/ltmm3/caso/fdf')
Fortran runtime error: Cannot allocate memory

By the way, monitoring the ram usage (of totally 4gb + 5Gb swap) , syrthes used only 613 Mb so i can't understand what does "cannot allocate memory" means really.

Andrea

Hello,

The radiative module of SYRTHES uses something in the area of n_boundary_faces*n_boundary_faces/2 storage, so memory cost goes up very quickly (due to the dense symmetric visibility factor matrix).

Looking at the source code, the error seems to appear when writing that form factor matrix, and is probably due to some buffer allocation issue in he Fortran code.

As this is probably related to the Fortran runtime, there is probably not much to do about it (though you may check environment variables handled by you Fortran runtime in case there are options related to buffer sizes), but if you do not need it, you may simply deactivate output of this array by defining:

'STOCKAGE DES FACTEURS DE FORME SUR FICHIER=' 'NON'

(instead of 'OUI') in syrthes.ray.

Best regards,

Yvan