Are you writing your own code or using Fluent or any other software.

For own code, also how are you reading mesh file or are you creating own mesh within the code. As far as gravity force are concerned, the Naiver-stokes should be used with gravity force on.

Dear Ashwani, the answer to you question would be: yes, I'm writing my own code, using random distribution function in C++ to define their random position in define volume/domain, and all sand grain are inside, but the problem is that some of these do not touch each other, which doesn't correspond to physical phenomenon. I would like to "settle them down", if you know what I mean. Concerning Navies-Stokes equation, that's fine, I'm using full NSE with all terms included.

Thanks a lot for having interest in my topic,

Regards,

Nevena

I think you might need to use DEM model (Discrete Element Method) to simulate the sand deposition

Nevena.

It seems to me that your problem is the spatial geometry. Before proceeding further ask you: Have you found a two-dimensional solution for circles of different diameters?

Explain. Working first in a two-dimensional solution may be simpler extrapolation to three-dimensional structures.

Dear Mr. Maestri,

I wanted to keep the problem of creating domain separated from calculation and simulation, therefore I suppose that 2D/3D setting doesn't change the complexity in this "physical" phase, as in 3D there are simply spheres and a bounding box, whereas in 2D cycles and rectangle are present . Until now I have succeeded to create domain with 0.1 porosity value (the sample is quite well packed) only that the smallest spheres inside still levitate. I would like them more to settle down on the top of other already inserted spheres. Nevertheless, I do understand, that there is way to do this, and it is quite complex (regarding observing forces among spheres), but somehow I want to focus on calculation and NSE discretization rather than to spend a lot of time on creating domain. That's why I have wondered, if someone here on RG could have a quick hint how to do it fast and effective.

I have attached newly created domain with porosity value of 20%, where these levitating spheres are to be seen.

Any suggestion is of course more than welcome!!

Thank you very much,

All the best and pleasant upcoming holidays,

Nevena