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ChannelOodles Want to prescribe mass flux instead of mean velocity

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Old   September 22, 2008, 07:01
Default Hi Tammo, I am having exact
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Markus Weinmann
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Hi Tammo,

I am having exactly the same problem with prescribing a mass flux instead of Ubar.

The mas flux through cyclic patches is obviously zero.

Have you found a way to compute the mass flux through your domain?



Regards,
Markus
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Old   September 22, 2008, 11:25
Default Hi I have done something si
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Niels Gjoel Jacobsen
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Hi

I have done something similar once upon a time. As you are having the flowDirection, I believe something like this would give you the flux:

scalar flux = sum(pos(flowDirection & mesh.boundary()[patchID].Sf()) * phi.boundaryField()[patchID])

where patchID is referring to the cyclic patch in question. As the face-normal is pointing in opposite directions on the two cyclic patches the inner product will yield opposite sign, thus the "pos" part of the entry filters all opposite phis out of the summation, and voila

Have fun,

Niels
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Old   September 22, 2008, 12:23
Default Brilliant, it does exactly wha
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Brilliant, it does exactly what I need.

Thank you very much!
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