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How to check the convergence of the CFX solver?

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Old   May 24, 2013, 04:30
Default How to check the convergence of the CFX solver?
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Hello,
I would like to know how i can make sure that my solver is definitely converging. In other words, what should i check in the out. file ? (how should the residual values be?)
Knowing that i am using:
-steady state solution
-CFX stand alone mode
-High resolution scheme
PS: The FAQ of CFD online did not help me at all!
Thank you,
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Old   May 24, 2013, 06:13
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There is a section in the CFX documentation on obtaining convergence.
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Old   May 24, 2013, 06:24
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What is your own method?
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Old   May 24, 2013, 06:26
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Glenn Horrocks
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Residuals always, imbalances sometimes, other important parameters (lift, drag, pressure loss) sometimes.
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Old   May 24, 2013, 06:31
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would you please explain in details what you check exactly in the residuals?
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Old   May 24, 2013, 06:40
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Have you read the section on obtaining convergence? I hope you are not expecting me to re-type the entire chapter of the documentation.
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Old   May 24, 2013, 06:48
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Of course not!
Ok! and thank you very much for your help
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Old   May 24, 2013, 06:57
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Another useful resource:

http://www.computationalfluiddynamic...pendent-study/

In fact, it is worth reading all of the LEAP Australia blogs as there is lots of useful information - which would save lots of people having to make forum topics.
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Old   May 24, 2013, 07:00
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Thanks a lot Stuart
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Old   May 30, 2013, 05:46
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Hi, im new to OpenFoam.

I simulated a cyclon. The results in paraview are looking good, compered to other cylon simulations with cfd.

Now I want to do a Convergence Study with the pressure drop, but I dont know how i can implement to OpenFoam to calculate the pressure drop. In the tutorial that i use, there is a folder created "forces" in witch there is a text data "forceCoeffs.dat". There is the cd-Value saved. I can export these data to excel and do the Convergence Study with the cd-Value, but i want to do it with the Pressure drop. But the Pressure drop is not calulated. Can someone explain how to do it. I read through "computationalfluiddynamics.com.au/convergence-and-mesh-independent-study/" but it is mentioned that you can do it with the pressure drop, but it is not discribed how.
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Old   May 30, 2013, 05:57
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This is the CFX forum, try the openfoam forum.
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