Studying the movement of on air bubble in presence of nano particles by interFoam

sinhavivekananda318 · February 16, 2023, 17:30

Hello all,

I am currently working on gas-liquid-solid flow simulations. I have correctly simulated the movement of an air bubble by interFoam. Now, I want to disperse nano particles in my system and want to initiate the flow of the air bubble.
I understand that I need to incorporate lagrangian framework into Eulerian model, but I dont know how to modify interfoam in order to disperse particles in the system.
Can you guide me in this?

Regards
Dr. Vivekananda Sinha

Bloerb · February 17, 2023, 11:28

There are dozens of different options. It all depends on the particle size and type of interaction. The questions would be:
Are the particles way smaller than the mesh, about the size of a cell, several cells in size. Is it a one way or two way coupling. In other words does the particle movement influence the flow, or does the flow influence the particle movement. Are the particles just following the flow for example, or can they have an independent velocity. The reason for the mesh influence is that, you need to modify the velocity of the cell and it is of extreme importance if there is just one particle in there, or several, or if a particle is bigger than a cell, because the drag it has will create a wake etc.

There are particle solvers like MPPICInterfoam build in (Multiphase Particle-in-Cell Method). You can add lagrangian particles to a flow calculation with the lagrangian flow solvers as well.

You might however want to take a look at "Liggghts". A library for lagrangian particle simulations, that you can couple with openfoam.

sinhavivekananda318 · February 17, 2023, 15:16

Hi Bloerb,

Thanks for your patient reply. Just for your information I would like clarify some of the points you mentioned.
1. My system is static and the particles would be moving towards the interface.
2. As I told you that my particles are of nano meter size, so there size would be smaller than the mesh.
3. Since, I am starting with a static system, so no flow velocity will be there and the particles will on there own. I want to see whether they reach to the air-water interface after injection or not.
4. Meanwhile if I add a spherical air bubble by setFields, I would also want to see whether the independent movement of the particles have any effect on that air bubble or bubbles ( if I create multiple bubbles).

As you said MPPIC is a built in solver, can I have air water interface and then injection of particles in my system..Also, can I have particles of nano meter size in the injection?. I seek discussion with you on this matter.

Regards
Dr. Vivekananda Sinha

Bloerb · February 17, 2023, 16:04

I am sadly not an expert in this area. The outline I have given is however the main distinction between the different classes of DEM methods there are. Without spending some time looking at it, I can't answer all of those fully. I am unsure what all the limits for the MPPIC method are Some of these methods only apply to really dense particle clouds, others only to very dilute clouds. So particle-particle interaction might be handled differently depending on the specifics. My understanding is that MPPICInterFoam does what you want. It assumes that the particles are small in comparison to the grid, allows for particle injection etc. It can only handle spherical particles, at least without coding your own drag models. So that might be an issue. Otherwise you might want to look at the Multiphase particle-in-cell method in some textbook to see if it violates one of your demands.

February 16, 2023, 17:30	Studying the movement of on air bubble in presence of nano particles by interFoam	#1
sinhavivekananda318 New Member Vivekananda Join Date: May 2017 Location: Cardiff, UK Posts: 27 Rep Power: 9	Hello all, I am currently working on gas-liquid-solid flow simulations. I have correctly simulated the movement of an air bubble by interFoam. Now, I want to disperse nano particles in my system and want to initiate the flow of the air bubble. I understand that I need to incorporate lagrangian framework into Eulerian model, but I dont know how to modify interfoam in order to disperse particles in the system. Can you guide me in this? Regards Dr. Vivekananda Sinha

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February 17, 2023, 11:28		#2
Bloerb Senior Member Join Date: Sep 2013 Posts: 353 Rep Power: 21	There are dozens of different options. It all depends on the particle size and type of interaction. The questions would be: Are the particles way smaller than the mesh, about the size of a cell, several cells in size. Is it a one way or two way coupling. In other words does the particle movement influence the flow, or does the flow influence the particle movement. Are the particles just following the flow for example, or can they have an independent velocity. The reason for the mesh influence is that, you need to modify the velocity of the cell and it is of extreme importance if there is just one particle in there, or several, or if a particle is bigger than a cell, because the drag it has will create a wake etc. There are particle solvers like MPPICInterfoam build in (Multiphase Particle-in-Cell Method). You can add lagrangian particles to a flow calculation with the lagrangian flow solvers as well. You might however want to take a look at "Liggghts". A library for lagrangian particle simulations, that you can couple with openfoam.

February 17, 2023, 15:16		#3
sinhavivekananda318 New Member Vivekananda Join Date: May 2017 Location: Cardiff, UK Posts: 27 Rep Power: 9	Hi Bloerb, Thanks for your patient reply. Just for your information I would like clarify some of the points you mentioned. 1. My system is static and the particles would be moving towards the interface. 2. As I told you that my particles are of nano meter size, so there size would be smaller than the mesh. 3. Since, I am starting with a static system, so no flow velocity will be there and the particles will on there own. I want to see whether they reach to the air-water interface after injection or not. 4. Meanwhile if I add a spherical air bubble by setFields, I would also want to see whether the independent movement of the particles have any effect on that air bubble or bubbles ( if I create multiple bubbles). As you said MPPIC is a built in solver, can I have air water interface and then injection of particles in my system..Also, can I have particles of nano meter size in the injection?. I seek discussion with you on this matter. Regards Dr. Vivekananda Sinha

February 17, 2023, 16:04		#4
Bloerb Senior Member Join Date: Sep 2013 Posts: 353 Rep Power: 21	I am sadly not an expert in this area. The outline I have given is however the main distinction between the different classes of DEM methods there are. Without spending some time looking at it, I can't answer all of those fully. I am unsure what all the limits for the MPPIC method are Some of these methods only apply to really dense particle clouds, others only to very dilute clouds. So particle-particle interaction might be handled differently depending on the specifics. My understanding is that MPPICInterFoam does what you want. It assumes that the particles are small in comparison to the grid, allows for particle injection etc. It can only handle spherical particles, at least without coding your own drag models. So that might be an issue. Otherwise you might want to look at the Multiphase particle-in-cell method in some textbook to see if it violates one of your demands.