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Old   December 19, 2013, 01:50
Default Convergence
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EMAVI V SURYA SAMPATH
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Hi all,
(In FLUENT 14.5)

My solution is converged and all the flow rates etc got balanced. Even my plots are according to my expectations. But, the residuals got settled at e-02.

Any tips or tricks to make lower these residuals , at-least till e-04.

1. Tried by changing URF's. Need any other suggestions.
2. Done standard initialization ( Tried with hybrid as well, but obtained same result)

3. Trying for first order convergence


Will be glad if anyone can reply .

Thanks and Regards,
Sampath Emani
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Old   December 19, 2013, 12:00
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Yogesh Patil
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If you are satisfied with the results then you shouldn't worry about the residual values. Residual is one of convergence criteria and not the convergence criteria. You can also monitor variables at various location to make sure that solution is converged.

If you have natural convection in your problem then you are more likely to get residual which you are getting. Try flipping URF for pressure and momentum if you are using seggregated solver.
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Old   December 20, 2013, 01:06
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EMAVI V SURYA SAMPATH
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Hi,

Thanks for the reply.

I gave outflow boundary condition to the outlet. Hence, the residuals got stuck at e-02. When i tried by changing it to pressure outlet, residuals got reduced till 4.
this is for species transport simulation.

Regards,
Sampath emani.
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