Numerical Simulation of Fluidization and Sedimentation Phenomena

Motivated by the direct numerical simulation of particulate flow (i.e., of the motion of fluid-particle mixtures) the authors of this paper, with the assistance of several collaborators, have introduced some years ago a computational methodology based on a fictitious domain formulation involving distributed Lagrange multipliers defined over the particles; this approach allows the flow computations to be done on a fixed space region of simple shape, giving thus to the practitioners the possibility of very fast solvers to treat, for example, the diffusion and the incompressibility if we assume that the fluid is viscous and incompressible. The above methodology will be briefly discussed in the next section and then applied to the direct simulations of the fluidization of 1204 identical rigid solid spherical particles contained in a “bed” of simple shape and of the sedimentation of 6400 disks in a 2D rectangular box. For more details on the methodology briefly discussed in this paper and for further numerical results obtained with it see [GHJ97, GPH98, PGH98, GPHJ99, GPH99, Pan99].