Hey, I am trying to simulate a solid-gas fluidized bed by using a UDF for Drag coefficient. If I simulate with Syamlal or Gidaspow for drag coefficient there is no problem. But if I use a UDF i always get the following error: reversed flow in 56 faces on pressure-outlet. # Divergence detected in AMG solver: mp-x-momentum -> Decreasing coarsening group size!
# Divergence detected in AMG solver: mp-x-momentum -> Increasing relaxation sweeps!
# You may try the enhanced divergence recovery with (rpsetvar 'amg/protective-enhanced? #t)
# Divergence detected in AMG solver: pressure correction -> Turning off correction scaling!
# Divergence detected in AMG solver: pressure correction -> Increasing relaxation sweeps!
# You may try the enhanced divergence recovery with (rpsetvar 'amg/protective-enhanced? #t)
Error: Divergence detected in AMG solver: pressure correction I have no idea how to fix this problem, I already tried to lower the under-relaxation factors, but this didn't work. Maybe somebody can help me?
Hi Oumaima,
Could you upload the UDF you're using to compute the drag coefficient. it could be easier to debug your issue. For the reversed flow, did you try to relax your outflow by using "outlet vent"?
Hello, check your initial values and do not use zero values for any part!
Ali Jalayeri yes for my initial values I chose
inlet gas velocity = 1.25m/s
initial solide volume fraction = 0.6
static bed 0.204m
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