Turbulent Viscosity Ratio

April 23, 2003, 04:45

Dear All,

I got the message "Turbulent viscosity ratio reached the limit value of 1e05 in some cells" while working with FLUENT. However, when I tried to locate these cells with Iso-surface operation, the computed range of turbulent viscosity ration was from 0 to something like 3000 in my whold domain.The max. is obviously far below the limited 1e05. I know that the FLUENT will set the dissipation rate to necessary value whenever the max. is reached. Did this reduce the turbulent viscosity ratio exceeding 1e05 to be around 3000? or i am doing something wrong? Thanks a lot! xiang

April 23, 2003, 05:08

You can find some useful information posted several days ago.

April 23, 2003, 12:22

Hi xiang

You are not doing something wrong! because you think process is right, Fluent balances the turbulent viscosity ratio throught the dissipation. However, this management by Fluent could lead your simmulation to a erroneous results.

Therefore I sugguest that you keep the old files and open an intermediate iteration, plot the turbulent viscosity ratio contour plot for the whole domain, and identify those cells, then refine the mesh.

Regards

Alex Munoz

May 20, 2003, 13:46

Hi Alex,

Can you please write in detail how fluent exactly fluent balances the turbulent viscosity through dissipation ?

Thanks, Ashish

April 23, 2003, 04:45	Turbulent Viscosity Ratio	#1
xiang Guest Posts: n/a	Dear All, I got the message "Turbulent viscosity ratio reached the limit value of 1e05 in some cells" while working with FLUENT. However, when I tried to locate these cells with Iso-surface operation, the computed range of turbulent viscosity ration was from 0 to something like 3000 in my whold domain.The max. is obviously far below the limited 1e05. I know that the FLUENT will set the dissipation rate to necessary value whenever the max. is reached. Did this reduce the turbulent viscosity ratio exceeding 1e05 to be around 3000? or i am doing something wrong? Thanks a lot! xiang

April 23, 2003, 05:08	Re: Turbulent Viscosity Ratio	#2
beginner Guest Posts: n/a	You can find some useful information posted several days ago.

April 23, 2003, 12:22	Re: Turbulent Viscosity Ratio	#3
Alex Munoz Guest Posts: n/a	Hi xiang You are not doing something wrong! because you think process is right, Fluent balances the turbulent viscosity ratio throught the dissipation. However, this management by Fluent could lead your simmulation to a erroneous results. Therefore I sugguest that you keep the old files and open an intermediate iteration, plot the turbulent viscosity ratio contour plot for the whole domain, and identify those cells, then refine the mesh. Regards Alex Munoz

May 20, 2003, 13:46	Re: Turbulent Viscosity Ratio	#4
Ashish Guest Posts: n/a	Hi Alex, Can you please write in detail how fluent exactly fluent balances the turbulent viscosity through dissipation ? Thanks, Ashish

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