Simulation of fine powder suspensions

The hydrodynamic behavior of fine powder suspensions in micro scale is simulated with the assistance of computers and the effects of particle size, density, and cohesiveness and also fluid velocity pattern, density, and viscosity on the behavior of suspension is studied. Sedimentation, fluidized bed, and spouted bed as three cases of suspensions are considered.

The simulation method is based on, first, specifying the interactions of the particles with each other and with their surrounding, and second, calculating the trajectories of particles by using Newton's laws of motion. Stokesian dynamics method has been used in the calculation of hydrodynamic interactions of particles. The direct inter particle forces are represented in a pattern similar to Lennard-Jones force.

The velocity distribution of particles, bubble size and rising velocity in a fluidized bed, density profile of the bed, and other statistical characteristics of the bed have been calculated.