c) Flows with large size particles (Lundgren and Joseph model, volume of particles is accounted for in NS equations, but we do not solve for the flow around each particle).    Applications for flows characterized by high volume fraction of the suspended material, e.g., flows in fluidized beds.

Animation #12 6.93 MB:   Laminar flow (Re=1500) in an infinitely long channel.  Bottom half of channel is seeded initially with 4000 spherical particles.  With increased pressure gradient particles move, rotate and experience lift.  Difference between particle density and fluid density is only 1%, so after some time we end up with a pretty uniform distribution of the particles over the depth of the channel. Ratio between volume of particles and volume of channel close to 0.2, but locally this ratio was as high as 0.5.  As opposed to a model using point particles where there is no mechanism to account for the lift force on the particles, the present model is able to simulate this effect.