Turbulent viscosity limited to viscosity ratio of 1.0000000e+5

eespi002 · June 30, 2009, 08:41

Hi,

I was solving a simulation and as Fluent was in the process of iterations,
I saw this message after each iteration:

Turbulent viscosity limited to viscosity ratio of 1.0000000e+5 in 676 cells.

Can someone tell me what does this mean? why is it occuring? Explain please.

Thank you

Giuki · June 30, 2009, 11:07

Dear Edgard,

I've had the same situation, it depends on the problem you are trying to solve. Probably you have a problem with high level of turbulence. It is literaly what it's states, in 676 cells the viscosity ratio exceeds the value of 1e5. Fluent now limits the viscosity to that value.

You can change that limit in Solve --> Solution --> Limits let's say to a value of 1e6 and see if it still occurs, after some iterations, if the solution is having some convergence, you can set the limit back and see if it still occurs. A professor at my university stated that it should not really affect your solution much.

Good luck!

eespi002 · June 30, 2009, 13:17

Giuki,

Thanks for the response. I had another error.

Divergence detected in AMG solver: pressure correlation....

Would you know how to solve this.

Thanks in adavance.

Giuki · June 30, 2009, 13:24

Dear,

That is hard to tell, I once had it but cannot remember what the source was. I should have to see the set-up and BC you used, and even then I'm not sure I will find what couses the divergence error. Try searching in this forum. It seemed something was following the error message...pressure correlation...is there anything following these words?

Good luck!

June 30, 2009, 08:41	Turbulent viscosity limited to viscosity ratio of 1.0000000e+5	#1
eespi002 New Member Edgard Espinosa Join Date: Jun 2009 Posts: 18 Rep Power: 16	Hi, I was solving a simulation and as Fluent was in the process of iterations, I saw this message after each iteration: Turbulent viscosity limited to viscosity ratio of 1.0000000e+5 in 676 cells. Can someone tell me what does this mean? why is it occuring? Explain please. Thank you

June 30, 2009, 13:17	Divergence Detected in AMG Solver: pressure correlation	#3
eespi002 New Member Edgard Espinosa Join Date: Jun 2009 Posts: 18 Rep Power: 16	Giuki, Thanks for the response. I had another error. Divergence detected in AMG solver: pressure correlation.... Would you know how to solve this. Thanks in adavance.

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June 30, 2009, 11:07		#2
Giuki New Member Giuki Cael Join Date: May 2009 Location: Belgium/The Netherlands Posts: 13 Rep Power: 17	Dear Edgard, I've had the same situation, it depends on the problem you are trying to solve. Probably you have a problem with high level of turbulence. It is literaly what it's states, in 676 cells the viscosity ratio exceeds the value of 1e5. Fluent now limits the viscosity to that value. You can change that limit in Solve --> Solution --> Limits let's say to a value of 1e6 and see if it still occurs, after some iterations, if the solution is having some convergence, you can set the limit back and see if it still occurs. A professor at my university stated that it should not really affect your solution much. Good luck!

June 30, 2009, 13:24		#4
Giuki New Member Giuki Cael Join Date: May 2009 Location: Belgium/The Netherlands Posts: 13 Rep Power: 17	Dear, That is hard to tell, I once had it but cannot remember what the source was. I should have to see the set-up and BC you used, and even then I'm not sure I will find what couses the divergence error. Try searching in this forum. It seemed something was following the error message...pressure correlation...is there anything following these words? Good luck!