[Edy]

Hi,

Woaw, that s a quick reply !

Well, i have two terms :
- one due to evaporation at a heated wall, which is calculated using Kurul and Podowski model, and it is absolutely independent on the phase fraction
- one due to condensation in the bulk, which is directly proportional to the void fraction.

Best,

/Edouard

[alberto]

I would start not including them in the pEqn, and treating them as they appear in the momentum equation. If you notice this destabilizes the solution, you can easily move them to the pEqn.

Best,

[Edy]

Hi,

Ok, thank you very much for your help! I'll try that.

Best,

/Edouard

[chiven]

Originally Posted by alberto

The buoyantPressure BC is exactly a zeroGradient BC if p is not p_rgh. You might want to take a look at the code.

Best,

Hi, alberto, have a good day. Do you think it is possible to use the buoyantPressure BC in the twoPhaseEulerFoam solver through revising the code, like p_rgh substitute p, etc. I am wondering why OF1.7 doesn't do it like other multiphase flow solvers. Thank you in advance.

Chiven

[alberto]

It has been done by Oliveira and Issa in one of their papers:

Numerical aspects of an algorithm for the Eulerian simulation of two-phase flows, Numerical aspects of an algorithm for the Eulerian simulation of two-phase flows, Vol. 43, Issue 10--11, pp. 1177 -- 1198, 2003

I tried it some time ago when I started working on the multi-fluid code, and abandoned it, since it did not lead to significant improvements for what I need.

If your problem is specifying appropriate wall boundary conditions, you can do that either using p or p_rgh.

Best,

[chiven]

Thank you for the information. I am going to read it. Chiven

[Prash]

Dear People,

I have a small doubt over the boundary and initial conditions.
I am not quite sure about why do we need to specify both Ub and p at both inlet and outlet and the walls. My understanding is , we would not quite need pressure at the walls. at all.

I hope this makes sense

Best wishes
Prashant

[alberto]

Originally Posted by Prash

Dear People,

I have a small doubt over the boundary and initial conditions.
I am not quite sure about why do we need to specify both Ub and p at both inlet and outlet and the walls. My understanding is , we would not quite need pressure at the walls. at all.

I hope this makes sense

Best wishes
Prashant

You do not specify a value of Ub and p at the same boundary. Typically if you specify Ub, you use a zeroGradient condition for p, and viceversa. At walls a condition for p is typically zeroGradient.

You need a condition on each variable, or you would not be able to define the value of the variable on the boundary itself (in some cases you could actually extrapolate, but still you need to specify you want that).

Best,

[Kanarya]

hi,

I would like to simulate circulating fertilized bed in OpenFoam...I am new in it.Could somebody tell me which solvers are available for this.

thanks in advance

Recep

[avila.vc]

Hi.

I am trying to add a porous media to twoPhaseEulerFoam, I am confused about how to deal with the velocity equation. Can anyone give me a hint on how to modify UEqn file from twoPhaseEulerFoam?

[lavdwall]

Hi there!

I was wondering if there is a complete manual/documentation of the twoPhaseEulerFoam solver as it is programmed in OpenFOAM version 2.4.0? Thanks in advance

Kind regards,
Laurien

[cesarvenier]

Hi, Laurien

I don't think there is a "complete" documentation out there. Maybe you can look at this instead:

https://drive.google.com/file/d/0B2l...ew?usp=sharing

http://powerlab.fsb.hr/ped/kturbo/Op...chePhD2002.pdf

and then:

http://www.sciencedirect.com/science...32591011003652

http://www.sciencedirect.com/science...45793016301438

Hope it helps!

[us7]

Originally Posted by xiao

hmm... you are right. Indeed, the two-fluid (gas/liquid) problem and the porous media problem is different since in the two-fluid problem, both phase can have pressure, while for the porous media problem, on the fluid can have pressure. This issue is very tricky. I need to think more about it.

Hi Xiao,

I have very quick question related to twoPhaseEulerFoam. I am also working on porous media using twoPhaseEulerFoam with combination of Darcy(source). I have question related to pressure term.

This solver has pressure term which should be for each phase I guess. Can you give some hint how is it solving pressure?
Is it separate for each phase like Pa and Pb? Or its mixer pressure or average pressure? The reason of this question is that i want to add capillary pressure for porous media. Please correct if my way of asking is not correct.

Regards,
Umer

[minzhang]

Hello Paul,

I am wondering whether you worked your problem out at the end, and whether you could direct me to your papers/thesis for reference.

Here, I want to use twoPhaseEulerFoam to simulate a solid/liquid slurry transport in long horizontal pipes like in this reference.
Yang, Yan, Haoping Peng, and Chuang Wen. "Sand transport and deposition behaviour in subsea pipelines for flow assurance." Energies 12.21 (2019): 4070.

Your valuable comments would be greatly appreciated!

Thanks!
Min

Originally Posted by paul

Alberto,

I'm having problems with the particle-particle magnitude force (PPMagf) equation, which is in the alphaEqn.H file.

I am very new with this software as well as this type of fluid dynamics. I'm using the bed example and changing it to a liquid-solid settling model. When I include the packing limiter I get a Floating exception error (I'm assuming a division by zero). When I turn the packing limiter off the solids fraction rises above the packing limit and in some other locations I also get a negative solids fraction.

Do you have any suggestions?

Thank you,
Paul