Dear friends,

I want to simulate sedimentation of three dense solid phases into a liquid phase, how should I modify the solid-solid momentum transfer model. If I want to model the drag and friction force between the solid particles, what should I do using user Fortran? I mean how can I guarantee the convergence of the simulation results given I can realize the force using user Fortran?

Thanks,

Nessan

Hi Nessan,

The convergence of the simulation would be governed by lot of other parameters as well like the mesh, advection scheme, timestep ....

I suppose you want to incorporate your own model for drag force..

You can also use the Gidaspow model avaliable in CFX-library.

You will ahve to use the junction box subroutine... tell me what you want to incorporate so that i can help you further

Thanks, test!

(Eulerian-Eulerian Particle Model) In CFX solid pressure model (Giadaspow) was the only consideration for solid-solid momentum transfer. However, for the dense solid-liquid slurry, the momentum transfer between solid and solid due to shear, compression (or expansion) and collision is significant. In order to account for the momentum transfer due to translation and collision between solid particles, a source term has to be included in the momentum equation for solid phases.

So the drag between solid particles and solid shear stresses will be added. I never used User Fortran before. Could you please give me some hints.

Thanks again,

Nessan

Well Kinetic theory model will be helpful for this case. However it is not included in CFX-5.6, but should be avaliable in CFX-5.7 which should be released at the end of April or first week of may. For using fortran, you will have to learn a bit of the memory management scheme which CFX uses. Go through the section on user fortran in help manual. Get some help from your nearest CFX-support personnels..

Thank you very much, test.

Best regards,

Nessan