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agastyamit November 8, 2011 11:45

interaction between solid and fluid particles

I am trying to simulate flow in a domain with air as continuous fluid and water drops and another solid particles need to be particle transport fluid and solid respectively.

The problem is in domain definition, i can not find how to define the interaction between drops and solid particles. is it at all possible with CFX. (what i need is that the tracking of solid particles should stop when its track intersects the one of water drops)
I am trying this with langrangian method

can someone please suggest me if there is another way of doing this, or what i need to do to get particle interaction.


ghorrocks November 8, 2011 17:41

You are probably going to have to develop a model to do this. I have no experience in this area. Sounds tricky as particle tracking does not take into account the size of the particles so you are going to have to work out when a solid particle intersects a liquid particle.

This model may be better done in a eularian framework using a statistical approach. Then the extinguishing of particles just becomes a source term which is a function of the local volume fraction of the phases. Much easier, providing you can define the source term.

singer1812 November 8, 2011 17:46

Look up Particle-Particle collision in CFX help. I have no experience on this, but there is a particle to particle model in CFX. As to whether it pertains to what you need to model, I have no idea.

agastyamit November 10, 2011 10:11

Thanks, i am trying out both the suggestion.

particle-particle collision, so far as i understand, allows collision of same kind of particles. I need to look in detail if it can be used for collision of different kind of particles. or else i need a model of my own.


Graham81 November 10, 2011 10:35

If you end up having to model it yourself, I suggest considering the O'Rourke collision and coalescence model. It is relatively straightforward.

juliom November 17, 2011 08:56

dear friend, first of all you have to calculate some parameters first, in order to know if you will have particle intereaction. So, calculate if you will need one way coupling or two way cupling with particle collision.
If you are using particle collision you can define some targets, so when particles collisionm the tracking would finish..
YOu should calcualte first; stokes numbers, kolmogorov scales, Volume fraction of each phase, inter-particle space; and then you can conclude if you will need collisions models.

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