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Why does the convergence differ from actual residuals?

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Old   July 25, 2021, 16:01
Default Why does the convergence differ from actual residuals?
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Hi all,
does anyone have any insights into why any given case would not converge even though the plotted residuals are definitely below the max limits set?
Is this specific to solver/geometry/etc?

my fvSolutions:
    nNonOrthogonalCorrectors 0;
    pMinFactor      0.2;
    pMaxFactor      1.5;

        p               1e-3;
        U               1e-5;
        e               1e-3;

        // Possibly check turbulence fields
        "(k|epsilon|omega)" 1e-3;
If you compare this with the attached figure of residuals, we can clearly see that the max limits were reached much earlier than when it actually converged.
I do not notice any strange things in the log or any warnings etc.
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File Type: png resids.png (21.8 KB, 18 views)
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Old   July 26, 2021, 00:47
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Uwe Pilz
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Please look at the residuals of k and ε / ω first. May be there are larger residuals.
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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convergence, convergence criteria, of7, rhosimplefoam

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