Reply To: Divergence problem of the spray simulation with Eulerian wall film

[azhao]

Hi Rob,
Thanks for the great suggestions.
I decreased the particle time step from 0.0001s to 0.00002s. And the splashing is turned off. Also, the DPM domain is unticked. The error message now seems simpler than before, but the solution still blows off after 25 iterations as shown in the following:
It looks like the problem is in solving for the Eulerian wall film models by checking the huge residual of it. And the problem of turbulence quantities remains. The problem of a huge DPM parcel number is eliminated, I suppose it means most parcels are generated by splashing...
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Advancing DPM injections ....

Reversed flow on 956 faces (8.5% area) of pressure-outlet 12.

Reversed flow on 6391 faces (24.0% area) of pressure-outlet 13.

Reversed flow on 6832 faces (86.7% area) of pressure-outlet 14.
sub-iteration: 1 residual - h: 0.000000e+00; u: 0.000000e+00; v: 0.000000e+00; t: 0.000000e+00
Film time = 2.000000e-03 with timestep = 1.0e-04, (max_cfl: 0.000000e+00)
Injecting 25 particle parcels with mass 2e-08
number tracked = 275
Injecting 25 particle parcels with mass 2e-08
number tracked = 300
Injecting 25 particle parcels with mass 2e-08
number tracked = 325
Injecting 25 particle parcels with mass 2e-08
number tracked = 350
Injecting 25 particle parcels with mass 2e-08
number tracked = 375
Injecting 25 particle parcels with mass 2e-08
number tracked = 400
Eulerian wall film particles:
absorbed = 13
Injecting 25 particle parcels with mass 2e-08
number tracked = 412
Eulerian wall film particles:
absorbed = 24
Injecting 25 particle parcels with mass 2e-08
number tracked = 413
Eulerian wall film particles:
absorbed = 26
Injecting 25 particle parcels with mass 2e-08
number tracked = 412
Eulerian wall film particles:
absorbed = 27
Injecting 25 particle parcels with mass 2e-08
number tracked = 410
Eulerian wall film particles:
absorbed = 27

...............................................................................................................................................................................................................................
turbulent viscosity limited to viscosity ratio of 1.000000e+05 in 187343 cells
244.6249e-047.3816e-021.2243e-026.3270e-021.2860e+065.6663e-011.0639e+005:11:14 19976

Reversed flow on 3235 faces (33.1% area) of pressure-outlet 12.

Reversed flow on 8237 faces (57.1% area) of pressure-outlet 13.

Reversed flow on 5250 faces (67.6% area) of pressure-outlet 14.
temperature limited to 1.000000e+00 in 513405 cells on zone 10 in domain 1
temperature limited to 5.000000e+03 in 436656 cells on zone 10 in domain 1
sub-iteration: 1 residual - h: 1.976365e+12; u: 1.926994e+13; v: 8.212897e+12; t: 1.544663e+87
sub-iteration: 2 residual - h: 1.492813e+12; u: 6.872916e+12; v: 5.264992e+12; t: 5.808624e+87
sub-iteration: 3 residual - h: 1.102153e+12; u: 1.924995e+13; v: 8.212897e+12; t: 6.931355e+87
sub-iteration: 4 residual - h: 1.103431e+12; u: 6.872916e+12; v: 5.264992e+12; t: 5.808624e+87
sub-iteration: 5 residual - h: 1.103234e+12; u: 1.924995e+13; v: 8.212897e+12; t: 6.931355e+87
sub-iteration: 6 residual - h: 1.103234e+12; u: 6.872916e+12; v: 5.264992e+12; t: 5.808624e+87
sub-iteration: 7 residual - h: 1.103234e+12; u: 1.924995e+13; v: 8.212897e+12; t: 6.931355e+87
sub-iteration: 8 residual - h: 1.103234e+12; u: 6.872916e+12; v: 5.264992e+12; t: 5.808624e+87
sub-iteration: 9 residual - h: 1.103234e+12; u: 1.924995e+13; v: 8.212897e+12; t: 6.931355e+87
sub-iteration: 10 residual - h: 1.103234e+12; u: 6.872916e+12; v: 5.264992e+12; t: 5.808624e+87
Film time = 2.193750e-03 with timestep = 6.3e-06, (max_cfl: 9.051277e+05)
Maximum CFL reached. Reduce time step by factor of 2

turbulent viscosity limited to viscosity ratio of 1.000000e+05 in 257258 cells
254.9143e+008.5547e-039.2232e-042.5725e-036.8090e+594.7955e+071.5337e+005:09:00 19975

Reversed flow on 10219 faces (47.4% area) of pressure-outlet 12.

Reversed flow on 11966 faces (73.9% area) of pressure-outlet 13.

Reversed flow on 5496 faces (71.4% area) of pressure-outlet 14.
Stabilizing temperature to enhance linear solver robustness.
Stabilizing temperature using GMRES to enhance linear solver robustness.

Divergence detected in AMG solver: temperaturesub-iteration: 1 residual - h: 1.318278e+19; u: 6.973356e+17; v: 2.637542e+17; t: 6.959193e+88
sub-iteration: 2 residual - h: 1.320348e+19; u: 2.046648e+20; v: 2.037741e+20; t: 1.007706e+95
sub-iteration: 3 residual - h: 1.320801e+19; u: 6.973356e+17; v: 2.621847e+17; t: 1.212422e+101
sub-iteration: 4 residual - h: 1.320801e+19; u: 2.046648e+20; v: 2.037741e+20; t: 1.206597e+107
sub-iteration: 5 residual - h: 1.320801e+19; u: 6.973356e+17; v: 2.621847e+17; t: 9.390307e+112
sub-iteration: 6 residual - h: 1.320801e+19; u: 2.046648e+20; v: 2.037741e+20; t: 4.265750e+111
sub-iteration: 7 residual - h: 1.320801e+19; u: 6.973356e+17; v: 2.621847e+17; t: 1.152971e+109
sub-iteration: 8 residual - h: 1.320801e+19; u: 2.046648e+20; v: 2.037741e+20; t: 9.192200e+117
sub-iteration: 9 residual - h: 1.320801e+19; u: 6.973356e+17; v: 2.621847e+17; t: 5.623902e+123
sub-iteration: 10 residual - h: 1.320801e+19; u: 2.046648e+20; v: 2.037741e+20; t: 2.564501e+131
Film time = 2.196875e-03 with timestep = 3.1e-06, (max_cfl: 4.516040e+12)
Maximum CFL reached. Reduce time step by factor of 2

turbulent viscosity limited to viscosity ratio of 1.000000e+05 in 932236 cells

Divergence detected in AMG solver: temperature
Divergence detected in AMG solver: temperature