[liguifan]

I am going to study how two particles(sphere) move on free surface such as water.

Now I have build a tank with water(with Gmsh), but I am confused about the particles.

Do I need to use Gmsh to build the actually particles and put the boundary condition of the particle together with boundary condition with my tank? How to define the density of it?

Or I can rebuild the tank by adding two sphere holes inside of it to initial the particles' original location? I am new to this area and hope someone can give me some hint, which will be appreciated!