Bubble_simulation

mer · September 9, 2005, 09:43

Hi,
I want to simulate the motion of a bubble rising in a cylindrical tube
with interfoam. any help for a begineer.
thanks.

brahim · December 6, 2005, 10:20

hi,
look the twoPhaseEulerfoam case in the new version of Openfoam-1.2 or bubbleColumn case in old version OpenFoam-1.1.
enjoy,
brahim

alberto · December 6, 2005, 10:34

twoPhaseEulerFoam adopts a Euler-Euler approach, which is suitable if you want to simulate complex systems like a bubble column, with an high volume fraction of the dispersed phase.

If you need to simulate the motion of a single bubble studying, for example, its deformation, you should use a VOF model like (interFoam).

Alberto

mer · December 7, 2005, 05:32

Thank you for your response;
yes, I want to test my simulation with the vof method. I try in past with another code that use vof method, than I would perform it with OpenFOAM.
I began my simulation with a modified interfoam case cited in the code, but I encountred a problem the PISO algorithm:
in results, no trace of gas phase, only liquid.
(In first time I've got an error with pdRefvalue and correct it)

any contribution ?!

aurelia · March 22, 2006, 04:09

Hi!
I am trying to simulate a rising bubble of air in water with interFoam.
I do not manage to create a nice initial bubble of air.
I set gamma to zero in a vitual sphere, ie I wrote something called setgamma which says "set gamma to zero if the coordinate of the centre of the cells of the internal mesh verify the equation of the sphere with centre C0 and rayon R"
the cells at the virtual interface of the sphere are set to 0, but I would like to set them to 0.5 for exemple, to have a smoother interface
the best would be to know which cells are cut by the sphere, and to know the volume of the cell in each side of the cutting plane
In doxygen, I found function that give the cell at a position, is there a fuction that gives the cells cutting by a surface?

well, perhaps am i all wrong

should I create a mesh for the bubble and use moving mesh instead?
Hrvoje, as your phd worked on rising bubble I thought you could give me some advice. Because of my lack of knowledge in his language, I don't understand what he is doing but it seems that the bubble has its own mesh, isn't it?

I tried to run InterFoam with the "uggly" bubble, just to see if it will rise, but it does not...
at least after 1 s (with delta T=1e-05)
someone with experience in this topic could give me some hint?

thanks!
Aurelia

September 9, 2005, 09:43	Hi, I want to simulate the mo	#1
mer Member merrouche djemai Join Date: Mar 2009 Location: ain-oussera, djelfa, algeria Posts: 46 Rep Power: 17	Hi, I want to simulate the motion of a bubble rising in a cylindrical tube with interfoam. any help for a begineer. thanks.

December 6, 2005, 10:20	hi, look the twoPhaseEulerfo	#2
brahim New Member Brahim Aakti Join Date: Mar 2009 Location: Lucerne, Switzerland Posts: 23 Rep Power: 17	hi, look the twoPhaseEulerfoam case in the new version of Openfoam-1.2 or bubbleColumn case in old version OpenFoam-1.1. enjoy, brahim

December 6, 2005, 10:34	twoPhaseEulerFoam adopts a Eul	#3
alberto Senior Member Alberto Passalacqua Join Date: Mar 2009 Location: Ames, Iowa, United States Posts: 1,912 Rep Power: 36	twoPhaseEulerFoam adopts a Euler-Euler approach, which is suitable if you want to simulate complex systems like a bubble column, with an high volume fraction of the dispersed phase. If you need to simulate the motion of a single bubble studying, for example, its deformation, you should use a VOF model like (interFoam). Alberto __________________ Alberto Passalacqua GeekoCFD - A free distribution based on openSUSE 64 bit with CFD tools, including OpenFOAM. Available as in both physical and virtual formats (current status: http://albertopassalacqua.com/?p=1541) OpenQBMM - An open-source implementation of quadrature-based moment methods. To obtain more accurate answers, please specify the version of OpenFOAM you are using.

December 7, 2005, 05:32	Thank you for your response;	#4
mer Member merrouche djemai Join Date: Mar 2009 Location: ain-oussera, djelfa, algeria Posts: 46 Rep Power: 17	Thank you for your response; yes, I want to test my simulation with the vof method. I try in past with another code that use vof method, than I would perform it with OpenFOAM. I began my simulation with a modified interfoam case cited in the code, but I encountred a problem the PISO algorithm: in results, no trace of gas phase, only liquid. (In first time I've got an error with pdRefvalue and correct it) any contribution ?!

March 22, 2006, 04:09	Hi! I am trying to simulate a	#5
aurelia New Member Aurelia Cure Join Date: Mar 2009 Location: Lund, Sweden Posts: 18 Rep Power: 17	Hi! I am trying to simulate a rising bubble of air in water with interFoam. I do not manage to create a nice initial bubble of air. I set gamma to zero in a vitual sphere, ie I wrote something called setgamma which says "set gamma to zero if the coordinate of the centre of the cells of the internal mesh verify the equation of the sphere with centre C0 and rayon R" the cells at the virtual interface of the sphere are set to 0, but I would like to set them to 0.5 for exemple, to have a smoother interface the best would be to know which cells are cut by the sphere, and to know the volume of the cell in each side of the cutting plane In doxygen, I found function that give the cell at a position, is there a fuction that gives the cells cutting by a surface? well, perhaps am i all wrong should I create a mesh for the bubble and use moving mesh instead? Hrvoje, as your phd worked on rising bubble I thought you could give me some advice. Because of my lack of knowledge in his language, I don't understand what he is doing but it seems that the bubble has its own mesh, isn't it? I tried to run InterFoam with the "uggly" bubble, just to see if it will rise, but it does not... at least after 1 s (with delta T=1e-05) someone with experience in this topic could give me some hint? thanks! Aurelia