[Rezaa70]

I'm trying to simulate in Fluent a 3D compressible flow in coil that coverwith water, in order to study the temperature profiles in the coil.

M=1.1

Boundary conditions:
- inlet: pressure-inlet (direction z)
- outlet: pressure-outlet


Turbulence: standard K-Epsilon. Intensity of turbulence



at first iterations, three errors appear:
# Divergence detected in AMG solver: coupled --> Decreasing coarsening group size!
# Divergence detected in AMG solver: coupled --> Increasing relaxation sweeps!
# Divergence detected - temporarily reducing Courant number to 0.5

It also gives me some messages saying: turbulent viscosity limited to viscosity ratio of 10^5 in 100250 cells

I don't know what it means and how to solve it... I'm really desperated! :S Any ideas??

Thanks in advance!

[pvtschultz]

I've experienced this with the VOF model. The solution was to increase mesh density around the active regions, greatly reduce the time step, and as a last resort get away from a coupled solver.