[samiam1000]

Dear All,

I am pretty new with the multi-phase modeling.

I am going to simulate a bubble-column, in order to investigate, but I can not understand very well all the settings. Is there a good tutorial to start from, according to you?

Thanks a lot,
Samuele

[zandi]

Originally Posted by alberto

I have come to the conclusion that the major culprit is the TomiyamaAnalytic drag. I ran the case with both Schiller-Naumann and Tomiyama-Kataoka-Zun-Sakaguchi drag law (I implemented it), and I don't see the very strange velocity profile that comes out with the TomiyamaAnalytic implementation.

Is the grid you are using here the same you had when you ran with 2.3.0 and obtained good results, or did you coarsen it? I don't see a lot of fluctuations in the bubble plume with the Schiller-Naumann drag. The case with Tomiyama-Kataoka-Zun-Sakaguchi is still running, so I will know soon.

Dear Dr. Passalacqua
Is fluctuations in plume of bubble in this solver due to drag model? Schiller-Naumann can do fix it? in water and air mixing flow.

Really Thank you
Fatema

[smhosseini]

Hi everybody,

I want to simulate a bubble column. In this case, the gas phase is absorbed by the liquid phase and there is a reaction in the liquid phase. I'm going to use OpenFOAM. I want to combine twoPhaseEulerFoam and reactingFoam.

Could you tell me your idea about this case? Do you have any suggestion for me?

what is the term of + fvOptions(rho, Yi) in the YEqn.H of reactingFoam?

Looking forward to your answers.
Thanks in advance.

[zandi]

Originally Posted by zandi

Dear Dr. Passalacqua
Is fluctuations in plume of bubble in this solver due to drag model? Schiller-Naumann can do fix it? in water and air mixing flow.

Really Thank you
Fatema

O

I fixed it!! it is because of deltaT and maxCo
delta and courant number

[surya.tdr]

can any one help to simulate my bubble column which is having co-current flow of air and water. Is it possible to provide boundary conditions for inlet air and water or is it necessary to define a stagnant liquid column?

[zandi]

Originally Posted by surya.tdr

can any one help to simulate my bubble column which is having co-current flow of air and water. Is it possible to provide boundary conditions for inlet air and water or is it necessary to define a stagnant liquid column?

Hi
yes it is. I don't know alot about "co-current flow of air and water" but you can with different U files for water and air .

[smhosseini]

Originally Posted by surya.tdr

can any one help to simulate my bubble column which is having co-current flow of air and water. Is it possible to provide boundary conditions for inlet air and water or is it necessary to define a stagnant liquid column?

Hi surya,

You can use bubbleColumn case in OpenFOAM tutorial and you should only add inlet and outlet for liquid phase, OpenFOAM solves momentum equation for liquid phase and so, there isn't any limitation for liquid flow.

bests.

[surya.tdr]

Originally Posted by smhosseini

Hi surya,

You can use bubbleColumn case in OpenFOAM tutorial and you should only add inlet and outlet for liquid phase, OpenFOAM solves momentum equation for liquid phase and so, there isn't any limitation for liquid flow.

bests.

Thanks for your reply..
I am trying to do in fluent.. If you have similar tutorials can you please upload..

--------------

Originally Posted by zandi

Hi
yes it is. I don't know alot about "co-current flow of air and water" but you can with different U files for water and air .

Thanks for you reply..
i am sorry i didnt understand what is this U files?

[smhosseini]

Hi friends,

Could you please take a look on my post in this link:
http://www.cfd-online.com/Forums/ope...tml#post567674

Is it possible to add mass transfer equation to twoPhaseEulerFoam solver according to my problem?
Do you have any better Idea for me?
Any suggestion will be kind of you.

Best Regards

Mohsen

[alberto]

Originally Posted by smhosseini

Hi friends,

Could you please take a look on my post in this link:
http://www.cfd-online.com/Forums/ope...tml#post567674

Is it possible to add mass transfer equation to twoPhaseEulerFoam solver according to my problem?
Do you have any better Idea for me?
Any suggestion will be kind of you.

Best Regards

Mohsen

I would suggest you use reactingTwoPhaseEulerFoam included in OpenFOAM-dev (from the OpenFOAM foundation, just to clarify: https://github.com/OpenFOAM/OpenFOAM-dev/commits/master )

Best,

[demichie]

Hi Alberto,
looking at reactingTwoPhaseEulerFoam I have not found in the alpha equation any term accounting for mass transfer. I only had quick look so I may be wrong, also because there are a lot of changes in the solvers structure from OpenFoam 2.4.0.
Is this correct?

Thank you
Mattia

[smhosseini]

Originally Posted by alberto

I would suggest you use reactingTwoPhaseEulerFoam included in OpenFOAM-dev (from the OpenFOAM foundation, just to clarify: https://github.com/OpenFOAM/OpenFOAM-dev/commits/master )

Best,

Hi alberto,

Thank you very much for your reply. I'll try it.

Best Regards

[zandi]

Originally Posted by surya.tdr

i am sorry i didnt understand what is this U files?

sorry to answer late
it is velocity file (in 0 folder)

[masoudsh]

Hi

I want to simulate bubbly flow.
I want to use twophaseEulerfoam or reactingtwophaseEulerfoam.
which one I use for simulate?
and what is the different between them?

THANKS

[Andrea_85]

Originally Posted by demichie

Hi all,
I have attached a .pdf describing how the drag terms K_1in2 and K_2in1 contribute to the total drag term K. In addition to there terms there is also the drag computed when neither phase is truly dispersed. Here there is the code taking into account this "segregated drag" (model_->K()):


if (model_.valid())
{
x() += model_->K()*(f1() - f2());
}

My problem is that the term f1-f2 can be negative...
I think instead for the segregated case the following formulation should be used (always positive, null when one phase is fully dispersed, and maximum when none of the phases is dispersed):


if (model_.valid())
{
Info<< "FIRST f1 min.internalField()" << endl;
x() += model_->K()*(1 - f2()) * f1();
}

Ciao
Mattia

Hello,

i am trying to understand how blending is handled in twoPhaseEulerFoam (v1706). For what i understood by reading the source code we have 3 cases:

1) alpha <= maxFullyDispersedAlpha.phase1. The drag model for phase1 dispersed in phase2 is used (K1in2).

2) alpha > maxFullyDispersedAlpha.phase2. The drag model for phase2 dispersed in phase1 is used (K2in1).

3) maxPartlyDispersedAlpha.phase1 =< alpha <= maxPartlyDispersedAlpha.phase2. A linear combination of the 2 drag models is used. Something like

K() = f1*K1in2 + f2*K2in1

Is this correct?

And if I specified a segregated drag model to handle cases when none of the phase is truly dispersed, where does it come into play? When maxPartlyDispersedAlpha.phase1 < alpha < maxPartlyDispersedAlpha.phase2 is the segregated drag model used, instead of the linear combination?

ps i edited since maxFullyDispersedAlpha and maxPartlyDispersedAlpha are defined for both phases.

Thanks,

Andrea