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-   -   # Divergence detected in AMG solver: temperature -> Increasing relaxation sweeps! (http://www.cfd-online.com/Forums/fluent/86740-divergence-detected-amg-solver-temperature-increasing-relaxation-sweeps.html)

pastarox March 31, 2011 15:00

# Divergence detected in AMG solver: temperature -> Increasing relaxation sweeps!
 
Hi all,

I'm a novice at FLUENT, and i'm having trouble getting my solution to converge.

I'm trying to do a heat transfer analysis on a 3D mesh, and I keep getting this error:
# Divergence detected in AMG solver: temperature -> Increasing relaxation sweeps!

I've tried changing the URF and the limit of the temperature.

Any ideas?

xrs333 March 31, 2011 15:12

try to reinitialize the solution, using more physical values, espacially for turbulent variables. you can check up turbulent viscosity ratio after initialization, it should not be too large.

arunintn March 21, 2013 06:31

dirvegen detected temperature
 
Hi,
I have the same problem. The project is about super sonic flow over a surface. we have the Tu%= 0.1. the speed of M=1.4
the gauge pressure is = 771643.9

Errors :
when the solution initialized it shows:
turbulent viscous ratio limited in some cells
absolute pressure limited
temperature limited

can some one suggest me the solution.

Abhya March 21, 2013 08:56

pastarox try :
solution controls -> advanced -> set cycle type to F cycle
.. Giving non physical source terms / boundary conditions may also cause it .. i had the same a coupe of times

arunintn March 23, 2013 03:58

Abhya, Can you explain what is non physical scource tearm. The changed cycle type is F-cycle but not working.

Now i'm getting absolute pressure limited..

can some one direct me or tell me why i have the problem.
I checked my grid it look good too..

Abhya March 23, 2013 08:17

Quote:

Originally Posted by arunintn (Post 415819)
Abhya, Can you explain what is non physical scource tearm. The changed cycle type is F-cycle but not working.

Now i'm getting absolute pressure limited..

can some one direct me or tell me why i have the problem.
I checked my grid it look good too..

unrealistic values ..
For example : I had a mass source term and an energy source term which depends on the mass source term as:
Energy source= (-mass source)*latent heat
I had forgotten the -ve sign earlier and this resulted in the error as yours...


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