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[swak4Foam] why continuity doesn't solve when p be fixedGradient in groovyBC? |
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July 4, 2013, 16:09 |
why continuity doesn't solve when p be fixedGradient in groovyBC?
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#1 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
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I have set p in outlet be:
Code:
(internalField(p)-50000) but it seems continuity doesn't solve for that as can be seen in the attached image.why?
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July 6, 2013, 20:27 |
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#2 |
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Niels Gjoel Jacobsen
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How come that you are not satisfied with 1e-18? I would say it was perfect from a continuity perspective.
Kind regards, Niels |
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July 7, 2013, 07:40 |
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#3 |
Senior Member
Ehsan
Join Date: Oct 2012
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hi Niels
in first time steps its a straight line without fluctuations.I think maybe it be an issue.
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Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
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July 8, 2013, 15:07 |
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#4 |
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Bernhard Gschaider
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No. For continuity error of 1e-18 to be a problem the system has to be really tiny. If your system is really that tiny the question is whether the continuum assumption is still valid (if it isn't then of course the question is whether the standard OF-solvers are still the right thing for you)
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July 8, 2013, 15:25 |
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#5 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
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dear Bernhard.I don't want that residuals to be less than 1e-18 ar such thing.
I focus on time 0 till around time 2e-5 that the continuity is a stright horizontal line.I ask why in this period (in figure) there are not any fluctuations in residuals.is it normal?how and why?!
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Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
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July 8, 2013, 16:20 |
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#6 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 26 |
I found out why its so!
in first time steps the residuals are of order 0f 1e-22 or 1e-21 and are very low in compare with later times(2e-5 to next)(I don't know the exact reason) then they appear as a line without fliuctuations,in next time steps continuity errors are a bit higher but are low enough as dear Benhard and dear Niels told to say continuity is satisfied.
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Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
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