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-   -   Injecting a different fluid after certain time (https://www.cfd-online.com/Forums/openfoam-solving/157430-injecting-different-fluid-after-certain-time.html)

Ananthakrishnan July 27, 2015 01:45

Injecting a different fluid after certain time
 
Hi..

Sorry to revive an old thread.

my doubt is somewhat similar.. My requirement is pipe is initially filled with fluid X. Q quantity of Fluid Y enters the pipe. After that Q quantity of Fluid Z has to enter through the same inlet (like flushing the pipe with fluids one after the other)

I have succeeded in flushing the pipe with Fluid Y. I dont know how to continue the simulation by changing the incoming fluid (Z).
I have defined the alpha.X alpha.Y alpha.Z.

Any hint will be greatly appreciated!!

thank you very much
Regards
Ananth

[ Moderator note: Moved from http://www.cfd-online.com/Forums/ope...let-fluid.html ]

Ananthakrishnan July 29, 2015 06:43

Injecting a different fluid after certain time
 
1 Attachment(s)
Hi,

I am performing a multiphase simulation where pipe is initially filled with mud water. Cement enters through the inlet. After Q vol of cement has been pumped, oil has to be pumped through the same inlet.


I have simulated the first step of pumping cement through mud filled pipe(using multiPhaseInterFoam) by setting inlet value of alpha.cement as one and rest 0. but cant understand how to inject oil now. I tried changing the alpha.oil to 1 and alpha.cement as 0 in the latest time step but it doesnt work.


I have attached all the case files for reference.
It would be very grateful If someone can point out the mistake in my case set up and/or give directions about how to proceed with this simulation.

Thank you very much
Regards
Ananth

ssss July 29, 2015 11:50

Well setting alpha.oil to 1 will certainly blow the simulation. Try changing the U.oil and U.cement

Ananthakrishnan July 30, 2015 00:09

hi..

I tried that..what i found was U.* is not required for multiphaseInterFoam(may be i am wrong..!!)!!! MultiphaseEulerfoam needs those.

thanks a lot for the idea..
Ananth

wyldckat August 2, 2015 11:35

Greetings to all!

@Ananth: There is a boundary condition named "uniformFixedValue" as of OpenFOAM 2.1.0: http://www.openfoam.org/version2.1.0...conditions.php - if you time things correctly, probably with an "inline table", you can get the U field to start/stop when you want and the same of the other alpha fields.

If you Google:
Code:

site:www.cfd-online.com/Forums uniformFixedValue
you'll find several examples.

Best regards,
Bruno

Ananthakrishnan August 2, 2015 11:53

Hi bruno..

oh okie.. sounds perfect..thanks a lot for the info. will check it out..

thanks
Ananth

Ananthakrishnan August 6, 2015 02:27

Hi bruno,

works perfectly with alpha.* as well.. !! thanks a lot

Regard,
Ananth


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