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-   -   turbulence viscosity ratio limited to 1 exp 5 (http://www.cfd-online.com/Forums/fluent/97616-turbulence-viscosity-ratio-limited-1-exp-5-a.html)

tichaona February 21, 2012 11:17

turbulence viscosity ratio limited to 1 exp 5
 
Hi colleagues

When I run simulation using a 1m/s wind, I dont get the turbulence viscosity ratio limited to 1 exp 5 in my solution. I get the message after changing the wind speed to 3m/s. What causes this.

I will appreciate any contribution.


Regrads

T.K

doronzo February 21, 2012 12:28

Re
 
hi

your Re number increases if you have a higher velocity, which probably means that the difference between your turbulent viscosity and molecular viscosity, or their ratio, also increases.

regards

federvo.mala February 21, 2012 23:59

Hello,

I have been also encountering that problem. What I do, although I am not sure it's correct, I simply increase the value of the turbolent viscosity in 'solutio controls'---> 'limits'.

doronzo February 22, 2012 15:09

not totally sure, but I think you can increase that value, which is the limit of your solution, in which case you sometimes avoid that ''problem''

delaneyluke February 24, 2012 07:15

Increasing the solution control limits won't solve your problem, it will just stop giving you warnings. The reason your turbulent viscosity goes up is more of a numerical problem. Try reducing your relaxation factors.

Regards
Luke


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