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problems with residuals in fluent.

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Old   February 9, 2009, 07:42
Default problems with residuals in fluent.
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I am having problems with my residuals in fluent. Tmy velocities and energy lines are both dropping to 1e-06 but my k , epsiolon and most important contuinity are not dropping below 1e-03??

i am modelling a simple closed cavity in a pipe. my inlet for the pipe has - a massflow = 0.305kg/s - turbulence intensity=5% - length scale=61mm (diamater of my pipe) - temp 291k


-gauge pressure of 0 -turbulence intensity=0.01 -length scale=61mm

i have messed around with my mesh to make it finer where i have seen high velocity or turbulence values but no matter how fine i make it i cannot get the residuals to drop??

i am using a p-v coupling= coupled with standard default values

canyone help or suggest anything?

thanks in advance

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Old   February 9, 2009, 08:30
Default Re: problems with residuals in fluent.
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Are you sure that your fields are not converged? if you disregard the residuals and look at your flow field variables

If you have been doing adaptive refining. I would suggest that you re-mesh your domain in your preprocessor. There you can control your resolution and hopefully get a good quality mesh.

otherwise try p-v coupling = simple.

have fun!

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Old   February 9, 2009, 08:46
Default Re: problems with residuals in fluent.
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yeah my flow walues seem to converge i.e.x,y,z velocities and my mass flow is conserved alongside my temp.

but its this contuinuituy k and epsilon value which is hovering around 1e-03 .

i ahve been refining my model manually in gambit not used any auto adaption?

tried p-v coupling =simple initially but i get error; divergence detected in AMG solver: pressure correction

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Old   February 10, 2009, 10:05
Default Re: problems with residuals in fluent.
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me again! sorry

i have tried using a turbulencevalues

turb ke =24 turbulence disspaption rate =4524

still no luck on k, eps and contuinuity converging?

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