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February 12, 2014, 05:38 |
compressibleInterFoam phase capturing
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#1 | |
New Member
Martin Bartonitz
Join Date: Nov 2013
Location: Hamburg, Germany
Posts: 2
Rep Power: 0 |
Hi Foamers,
i am not totally new to Foam, but new to the compressible part of foam. So here is my case. Its an bottle with a narrowing and a nozzle. For the initial conditions i have defined two phases (water=red, nitrogen=blue). The water will be pressed out of the bottle due the internal pressure (internal press = 52 bar, outlet press = 1 bar). The first picture shows the geometry in the YZ-plane. The water in modeled as an perfectFluid with R = 1e40, so that it is almost incompressible. After a few milliseconds of physical calculation time a recirculation zone establishes (thats what i expected). The recirculation zone is shown in the second picture (alpha) and the third picture (u_Z). At the bottom is the defined outlet with fixed pressure. All the rest is defined as a wall. It seems that foam is not really consistent with the phases, because in the recirculation zone is no water but nitrogen. So if the nitrogen phase hits the outlet, the velocity rises and in the end foam aborts the simulation due to the maximum number of iterations for T. So thats clear. How is the nitrogen phase possible? Could it come due to my setFieldsDict? Does foam fill all default faces with the following filedvalues? If so i should just change the default with the field Values. Quote:
Does anybody have an idea? Best regards Martin |
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February 12, 2014, 06:05 |
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#2 |
New Member
Join Date: Oct 2013
Posts: 15
Rep Power: 12 |
I would guess its a problem of your dynamic pressure.
The alpha also gets to negative values!? Maybe you get some strange pressure settings, that lead to something like vacuum. If you would post some information over your \0 files we could say more. Also a checkMesh would be helpful. |
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February 12, 2014, 06:16 |
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#3 | ||||||
New Member
Martin Bartonitz
Join Date: Nov 2013
Location: Hamburg, Germany
Posts: 2
Rep Power: 0 |
Hi pingat,
here is the checkMesh output: Quote:
U: Quote:
Quote:
Quote:
Quote:
Quote:
Alpha doesn't get "real" negativ values, more like: Min(alpha1) = -3.83397e-22 Min(alpha2) = -4.26326e-14 Best regards Last edited by mabar; February 12, 2014 at 07:21. |
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