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-   -   ubuntu twoPhaseEulerFoam seems to have 'bugs' (http://www.cfd-online.com/Forums/openfoam/91646-ubuntu-twophaseeulerfoam-seems-have-bugs.html)

freemankofi August 17, 2011 19:27

ubuntu twoPhaseEulerFoam seems to have 'bugs'
 
Hi,
I am not sure which is right or wrong, and will leave it to you to decide. I installed OF 2.0.1 on to my ubuntu machine. I copy twoPhaseEulerFoam and re-compled it as new solver and name it "fast....". When I ran bed2 tutorial case, the results were different. So, I re-compiled twoPhaseEulerFoam and saw different results. See the attached pictures label OF20.png for those results.

I want to stress that, the installed OF2.0.1 is the 'standard' one for ubuntu and NOT the source compilation.

Surprisingly, I didn't see that different for OF17 and OF2.0.x for Redhat by CentroOS. I have attached OF17 version. I idn't have OF17 for ubuntu since I deleted it before this test cases.

I don't know if there is 'bugs' in ubuntu's version or not....I will leave it to those guys who worked on it to test it themselves.

Lastly, OF2.0.x has PIIMPLE algorithim instead of PISO, probably borrowed the idea from Alberto's version. However, I got this message "PIMPLE: Operating solver in PISO mode", when I ran it. Is it using PISO or PIMPLE or both? any help will be much appreciated. I have to say, I don't have much experience with PISO/PIMPLE since I am SIMPLEC guy. Maybe, I need to get myself educated on this PISO/PIMPLE:)

thanks

freemankofi August 18, 2011 10:51

2 Attachment(s)
I forgot to attached the pictures:) See below...

alberto August 21, 2011 04:26

Quote:

Originally Posted by freemankofi (Post 320551)
Hi,
I am not sure which is right or wrong, and will leave it to you to decide. I installed OF 2.0.1 on to my ubuntu machine. I copy twoPhaseEulerFoam and re-compled it as new solver and name it "fast....". When I ran bed2 tutorial case, the results were different. So, I re-compiled twoPhaseEulerFoam and saw different results. See the attached pictures label OF20.png for those results.

I want to stress that, the installed OF2.0.1 is the 'standard' one for ubuntu and NOT the source compilation.

Surprisingly, I didn't see that different for OF17 and OF2.0.x for Redhat by CentroOS. I have attached OF17 version. I idn't have OF17 for ubuntu since I deleted it before this test cases.

I don't know if there is 'bugs' in ubuntu's version or not....I will leave it to those guys who worked on it to test it themselves.

I don't know what is causing this. I use openSUSE and compile from source ;-)

Quote:

Lastly, OF2.0.x has PIIMPLE algorithim instead of PISO, probably borrowed the idea from Alberto's version. However, I got this message "PIMPLE: Operating solver in PISO mode", when I ran it. Is it using PISO or PIMPLE or both? any help will be much appreciated. I have to say, I don't have much experience with PISO/PIMPLE since I am SIMPLEC guy. Maybe, I need to get myself educated on this PISO/PIMPLE:)
PISO simply does not iterate over the equations: it solves alpha, Theta, U, p, k, epsilon and proceeds in time.

PIMPLE is a combination of PISO and SIMPLE. In other words you can have outer correctors, if you set the appropriate keyword in the fvSolution PIMPLE sub-dictionary.

I'd be careful in using twoPhaseEuler for dense gas-particle flows with the kinetic theory: the phase fraction tends to go above the particle packing. The problem should not affect the "ppMagf" model. I fixed this difficulty in my code (not public yet), and if you need a reference, feel free to drop an email.

Best,


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