A Numerical Simulation of the Boycott Effect

The lattice Boltzmann method has been used to simulate the velocity field induced and the motion of an ensemble of particles during the sedimentation process in inclined tubes. The simulations show the trajectories and flow behavior of individual particles and particle-particle and particle-wall interactions as well as the formation of particle clusters. The global convection motion that was experimentally observed during such processes and tends to enhance the sedimentation process is also reproduced numerically. In addition we have found that smaller intermittent vortices, formed from the wakes of groups of settling particles, also play an important role in the sedimentation process and the final distribution of particles.