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Residuals not dropping in simpleFOAM.

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Old   April 26, 2018, 02:48
Default Residuals not dropping in simpleFOAM.
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Manideep Reddy
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Dear Foamers,

I am trying to simulate external flow over a geometry of an airship using simpleFoam solver and found that the residuals are not dropping at all after few iterations. So, I stopped the solver to see the pressure field. I found that the flow is not symmetric and pressure drag is more than five time that expected. Can anyone please explain why is this happening..?
Is this because I am using steady state solver for flows with unsteady phenomenon involved or other reason.

Thanks in advance.

TThanks in advance.
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Old   April 26, 2018, 03:09
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Uwe Pilz
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Depending on your Re number you may get an oscillatory solution. I recommend to use a transient solver like pimple- or pisoFoam. You see more directly where the problems of your models are.
Uwe Pilz
Die der Hauptbewegung überlagerte Schwankungsbewegung ist in ihren Einzelheiten so hoffnungslos kompliziert, daß ihre theoretische Berechnung aussichtslos erscheint. (Hermann Schlichting, 1950)
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