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-   -   Running problem when simulating liquid drop.(InterFoam) (http://www.cfd-online.com/Forums/openfoam-solving/107426-running-problem-when-simulating-liquid-drop-interfoam.html)

sharonyue September 26, 2012 22:20

Running problem when simulating liquid drop.(InterFoam)
 
1 Attachment(s)
hi Foamers:

I want to simulate the liquid drop .So I mimic the damBreak in the tutorial , grid the mesh , set the fields, but when I'm running with interFoam. the error said:

--> FOAM FATAL IO ERROR:
Unable to set reference cell for field p
Please supply either pRefCell or pRefPoint


file: /home/cfd/OpenFOAM/cfd-2.1.1/run/tutorials/multiphase/interFoam/laminar/mybreak/system/fvSolution::PIMPLE from line 54 to line 59.

From function void Foam::setRefCell
(
const volScalarField&,
const volScalarField&,
const dictionary&,
label& scalar&,
bool
)
in file cfdTools/general/findRefCell/findRefCell.C at line 125.

FOAM exiting


I have uploaded my case below. Thanks very much.

sharonyue September 28, 2012 20:58

I ve handled it.....

by correct the boundary condition of inlet in the PRGH.

sharonyue October 7, 2012 20:26

2 Attachment(s)
another problem arised.

I find that the fluid field vary with the mesh resolution.

when the mesh is fine and close. the liquid could not drop even. when the mesh is coarse the liquid could drop which would be close to the reality I think.

my case has been attached. anyone help me? thanks alot.

mybreak1 is the coarse mesh
mybreak2 is the fine mesh

sharonyue October 10, 2012 02:29

no boby here? im confused.

michielm October 10, 2012 05:03

Hi Sharon,
I took a look at your case and it seems that you have only walls (fixedValue 0 in U) and 1 inlet with a non-zero velocity. This is only possible if your liquids are compressible and if that is the case you cannot use interFoam like in the dambreak case.

Could you explain a bit more what you are trying to model exactly?!

Cheers,

Michiel

sharonyue October 10, 2012 11:44

Quote:

Originally Posted by michielm (Post 385870)
Hi Sharon,
I took a look at your case and it seems that you have only walls (fixedValue 0 in U) and 1 inlet with a non-zero velocity. This is only possible if your liquids are compressible and if that is the case you cannot use interFoam like in the dambreak case.

Could you explain a bit more what you are trying to model exactly?!

Cheers,

Michiel

hi Michiel
Thank you very much.


Do you mean if I only had walls and 1 inlet with a non-zero velocity,I should change another solver? But I dont know which solver is fit for this. Do u know?


otherwise, if I turned the upwall into atomsphere can I use the interFoam?


thank you very much for your warm-hearted

michielm October 10, 2012 14:23

1) I asked what exactly you are trying to model to find out whether you are indeed working with a compressible flow or just have a wrong BC somewhere. So if you want my advice on a different solver you will have to explain what you are trying to model first.

2) Yes, opening the upwall and turning it into atmosphere (e.g. zeroGradient velocity) would solve the problem. This will allow as many volume of air to flow out as there is liquid coming in from the inlet.

Cheers,

sharonyue October 11, 2012 20:51

Quote:

Originally Posted by michielm (Post 386001)
1) I asked what exactly you are trying to model to find out whether you are indeed working with a compressible flow or just have a wrong BC somewhere. So if you want my advice on a different solver you will have to explain what you are trying to model first.

2) Yes, opening the upwall and turning it into atmosphere (e.g. zeroGradient velocity) would solve the problem. This will allow as many volume of air to flow out as there is liquid coming in from the inlet.

Cheers,

hi Michielm,

actually I am modeling the liquid droping from a pipe no matter the liquid droping space is close or open. because I think the size of drop is smaller than the droping space.

seems like I should turn the upwall into atmosphere.

but I'm also curious about if the liquid dropped into a close space.

Thanks you very much.

mebinitap June 13, 2013 01:54

Dear all,
I want to see the deformations in a liquid droplet in presence of air flow. So I used a squared domain (in blockMeshDict file) and setFieldsDict for the droplet. I stated the boundaries as atmospheric and used the freeStream BC conditions for P and U. Problem is that droplet moves away leaving the domain if I put some value to velocity. Since I want to track the shape changes I have to move along with the droplet. Can anyone please give me a hint on that? Also are the BCs correct?

michielm June 13, 2013 05:51

Hi mebinitap,
First a quick note: please make your own thread with a question instead of hijacking the post of someone else.

I have a few questions to understand what exactly you want to model. Could you please include those in a new thread of your own:

- do you want the deformation of a static or a moving droplet? in case of a static droplet you will need something more than just the standard interFoam solver (or some trick with the BC)
- is it 2D or 3D?
- are periodic boundaries an option or do you have something non-periodic in your system?

mebinitap June 13, 2013 08:51

I am really sorry for the inconvenience caused. I posted my querries in the new thread:

http://www.cfd-online.com/Forums/ope...tml#post433808


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