Help needed with lubrication corrections.


I have a small problem with my Lattice Botlzmann simulations of a particle (hard sphere) suspensions, and I hope someone here can offer me some advice. I want to introduce lubrication corrections to the hard spheres when they are near contact as they seem to group together too much, even when in a fast fluid flow. I am looking at the paper of Nguyen & Ladd Phys. Rev. E. 66 046708 (2002) . It suggests to use boundary nodes between the fluid and solid nodes. However it is not clear to me what particle distributions these nodes should have and what I should be doing with these new boundary nodes, especially the ones that appear inside the particle radius. My particles do not rotate so I think there is no need to calculate the angular velocities. Normally I use the bounce back scheme when normal fluid nodes are streamed towards a solid node. Any suggestions about how I can correctly implement this or another lubrication scheme into my work would be very helpful for me.

Just to give you some more details I am using the Q15D3 model and BGK.

Thanks in advance for any replies!