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Boundary conditions for outlet

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Old   April 20, 2005, 13:41
Default For Fidap, we set boundary con
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Kim Sung
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For Fidap, we set boundary condition for outlets as:

BCFLUX( ADD, N3, ENTITY="outlet", CONSTANT=0.0 )
According to the Fidap manual:
BCFLUX: "normal component of total normal stress",
and "N3" is the outlet patches' normal direction.

and we did not set pressure conditions.
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Old   April 20, 2005, 13:50
Default Does Fidap make an assumption
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Does Fidap make an assumption about the outlet pressure or does it assume zero-gradient or some other kind of extrapolation?
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Old   April 20, 2005, 14:31
Default I can not find it from the man
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Kim Sung
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I can not find it from the manual. Probally they do it secretly;)
Thanks again for all your help!
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Old   April 21, 2005, 04:55
Default I've got an idea for you: try
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Hrvoje Jasak
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I've got an idea for you: try solving potential flow (using potentialFoam) and then start the Navier-Stokes solution from that - it may give you what you expect.

Hrv
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Old   April 5, 2006, 13:27
Default Hi Hrvoje Jasak, I am a n
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adil mardionglu
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Hi Hrvoje Jasak,


I am a new OpenFOAM user and I want to solve the continuity and 2 D navier stokes equations at steady state for incompressible flows. Where should I start? Can you give me some tips please.

Regards

adil
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Old   April 5, 2006, 14:25
Default Hi, Use simpleFoam. Start
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Hrvoje Jasak
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Hi,

Use simpleFoam. Start by reading the manuals and do the tutorial; if you want to know the algorithm, have a look at my Thesis (available on-line) or any standard CFD book like Ferziger and Peric for example.

Good luck,

Hrv
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Old   April 5, 2006, 15:26
Default Hi Jasak, Thanks for your
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adil mardionglu
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Hi Jasak,


Thanks for your advice but many thanks for your Phd Thesis.


Regards

adil
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Old   June 26, 2006, 03:18
Default Hi, I use interFoam to simula
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Hi,
I use interFoam to simulate rising bubbles
I am interested in the detachment of the bubble from the inlet (where air is injected), and its shape after detachment.
But the calculation are stopped because of the outlet conditions.
I just want the bubble to disappear from the domain so I set Neumann boundary condition for U, pd and gamma.
If the mesh is small enought, the first bubble disappear from the outlet. but from the next one, there is 4 small amount of air that stay on the boundary and keep growing and slow the computation
My colleague use a free surface with their own code, so I tried to set air in the last cells, but the results are very strange and it still slows too much the computation

Does anyone has experienced this problem before? or could guess some better outlet conditions?
Thank you
Aurelia
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