[hooshyar_rezaei]

I want to simulate a particle by DPM Method after that I want to apply a MHD for control volume that the particle will be effected by a magnetic field.The particle will stick to the wall and هt will be a magnet for attaching other particles. So how can I simulate that Particle after attaching by magnetic-wall, The particle itself becomes a magnet.
Any help would be appreciated
regards

[vinerm]

There are two scenarios mentioned in your post; one is that the particle attaches to the magnetic wall and second one is that the particle becomes a magnet and then attaches other particles. Do you want both of these scenarios to be applied or only the former one?

The former one is easier than the latter one but is not easy in itself. Fluent offers a trap bc and you can apply this via a UDF based on certain criteria, such as, if particle is within a certain proximity to the wall, it should move towards the wall and then get trapped. As far as the motion of the particle is concerned, you can apply extra force on the particle as a body force. This also needs to be done via UDF.

If you can elaborate more on the situation you want to implement, better suggestions could be expected.

[hooshyar_rezaei]

tanks a million,
As you said, "one is that the particle attaches to the magnetic wall and second one is that the particle becomes a magnet and then attaches other particles"
so I want to simulate both of them simultaneous. I mean, the particle attaches to the magnetic wall and after the attached particle becomes a magnet and then attaches other particles to that.
as a mather of fact, I simulated a channel that the particle attached to the wall by DPM and MHD but I don't know that does the particles have become a magnet for attaching the other particles???
and also do I should write a UDF for solve this problem???

[vinerm]

Particles will not become magnetic on their own. Furthermore, once particles are trapped by the wall, they disappear. Physically, it may not matter whether the wall attracts another particle or a particle attached to the wall until and unless a lot of particles get attached at same location and the magnetic strength increases at that particular location.