1209.1834 (Maria L. Ekiel-Jezewska)

Swarms of particles settling under gravity in a viscous fluid    [PDF]

Maria L. Ekiel-Jezewska

We investigate swarms made of a small number of particles settling under gravity in a viscous fluid. The particles do not touch each other and can move relative to each other. The dynamics is analyzed in the point-particle approximation. A family of swarms is found with periodic oscillations of all the settling particles. In the presence of an additional particle above the swarm, the trajectories are horizontally repelled from the symmetry axis, and flattened vertically. The results are used to explain how a spherical cloud, made of a large number of particles distributed at random, evolves and destabilizes.

View original: http://arxiv.org/abs/1209.1834