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turbulence viscosity ratio limited to 1 exp 5

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Old   February 21, 2012, 11:17
Default turbulence viscosity ratio limited to 1 exp 5
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tichaona
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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
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Old   February 21, 2012, 12:28
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Domenico
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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
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Old   February 21, 2012, 23:59
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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'.
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Old   February 22, 2012, 15:09
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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''
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Old   February 24, 2012, 07:15
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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.

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Luke
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