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-   -   Fixed Outlet Mass Flux boundary condition? (http://www.cfd-online.com/Forums/openfoam-pre-processing/77661-fixed-outlet-mass-flux-boundary-condition.html)

trex930 June 30, 2010 03:52

Fixed Outlet Mass Flux boundary condition?
 
Hi!

I read somewhere that Outlet Mass Flux boundary conditions are being discussed in this form... but i did many searches and couldnt find anything.

Basically my question is

Is it possible to set the mass flux at the outlet? If so, what boundary condtions do i have to call??

ie. type FixedOutletMassFlux: ?? (does this exist)

Thanks in advance Foamers!

Cheers,
T

herbert June 30, 2010 07:37

Hello,

try flowRateInletVelocity with a negative flowRate. I have never used it this way, but it should work though.

Regards,
Stefan

trex930 June 30, 2010 21:44

Hi Herbert,

I have indeed tried flowRateVelocityInlet but to no success. Any other options. I am unclear as to why its not working, but it seems that when the inlet velocity goes from positive to negative, the flow direction is still the same...:eek: which completely does not makesense to me! and then when it hits 0, a whole pile of errors come up. And as we all know, debugging openFoam errors are next to impossible.:p

Is it possible to just set the outlet velocity whilst leaving the inlet velocity as an $internalField? I have tried setting outlet velocity but it doesnt seem to work. Is there a different boundary condition that I should be using?

Cheers,
T


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