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Very strange problem with DPM combustion model

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Old   January 21, 2016, 07:47
Angry Very strange problem with DPM combustion model
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Hi guys.

I encountered very strange problem with ansys fluent
I try to simulate non-premixed combustion process in ansys fluent. I have injector which inject particles into pipe and after some time particles starts to evaporate. Evaporated particles ignites and produces heat, pressure and etc.

But I encountered strange particles behavior. Particles starts to appear in various places (please see video)

https://www.youtube.com/watch?v=pCqLEM73JOA

P.S. mesh is adapted by these gradients every time step.


Maybe someone have encountered same problem ? It would nice to know someone has solved this problem because I am out of ideas...

Code:
mark_pres   adapt/mark-with-gradients pressure space-gradient 2 yes 0.1 0.01 no 0 0 0
mark_vel    adapt/mark-with-gradients velocity space-gradient 2 yes 0.1 0.01 no 0 0 0
mark_turb   adapt/mark-with-gradients turb-kinetic-energy space-gradient 2 yes 0.1 0.01 no 0 0 0
dpmcolrat   adapt/mark-with-gradients dpm-collision-rate space-gradient 1 yes 0.1 0.01 no 0 0 0
dpmcons     adapt/mark-with-gradients dpm-concentration space-gradient 1 yes 0.1 0.01 no 0 0 0
dpmsen      adapt/mark-with-gradients dpm-omega-source space-gradient 1 yes 0.1 0.01 no 0 0 0
dpm2        adapt/mark-with-gradients dpm-sensible-enthalpy-source space-gradient 1 yes 0.1 0.01 no 0 0 0
dpm3        adapt/mark-with-gradients dpm-tke-source space-gradient 1 yes 0.1 0.01 no 0 0 0
dpm4        adapt/mark-with-gradients dpm-total-enthalpy-source space-gradient 1 yes 0.1 0.01 no 0 0 0
combine     adapt/combine-registers 0 1 2 3 4 5 6 7 8
display     adapt/display-register 9
adapt       adapt/adapt-to-register 9 0 0 yes
Output from console

Code:
Injecting 2 particle parcels with mass 3.36e-07 at t = 0.000661

Advancing DPM injections ....
  iter  continuity  x-velocity  y-velocity      energy           k       omega       fmean        fvar     time/iter
!  637 solution is converged
number tracked = 2159, escaped = 0, aborted = 0, trapped = 0, evaporated = 17, incomplete = 0, incomplete_parallel = 0, collided = 628, shed = 25
   637  9.3974e-04  8.4527e-09  5.1602e-09  6.6863e-08  1.9989e-08  3.7411e-06  0.0000e+00  0.0000e+00  0:00:06   30
   638  1.1210e+00  1.1691e-01  1.2427e-02  8.0195e+03  9.9664e+01  9.0283e+00  0.0000e+00  0.0000e+00  0:00:05   29

 absolute pressure limited to 5.000000e+10 in 4 cells on zone 8 
 Maximum PDF table enthalpy exceeded in 2 cells on zone 8 .
Minimum PDF table enthalpy exceeded in 3295 cells on zone 8 .

 turbulent viscosity limited to viscosity ratio of 1.000000e+05 in 12269 cells 
# Divergence detected in AMG solver: pressure coupled -> Decreasing coarsening group size!
# Divergence detected in AMG solver: pressure coupled -> Increasing relaxation sweeps!
# You may try the enhanced divergence recovery with (rpsetvar 'amg/protective-enhanced? #t)

Divergence detected - temporarily relaxing and trying again...

Divergence detected - temporarily relaxing and trying again...

Divergence detected - temporarily relaxing and trying again...

Divergence detected - temporarily relaxing and trying again...

Divergence detected - temporarily relaxing and trying again...
Maximum PDF table enthalpy exceeded in 6 cells on zone 8 .

Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: pressure coupled
Error at host: floating point exception
Minimum PDF table enthalpy exceeded in 3285 cells on zone 8 .

Error at Node 0: floating point exception

Error at Node 1: floating point exception

Error at Node 2: floating point exception

Error at Node 3: floating point exception

Error at Node 4: floating point exception

Error at Node 5: floating point exception

Error at Node 6: floating point exception

 turbulent viscosity limited to viscosity ratio of 1.000000e+05 in 12283 cells 

Error: floating point exception
Error Object: #f

Last edited by gamemakerh; January 21, 2016 at 08:10. Reason: update
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