Attractors of finite-sized particles: An application to enhanced separation

It is shown in the context of the periodically driven eccentric annular system that small rigid spherical particles advected in a time-periodic bounded flow can be represented by a dissipative dynamical system with simple or strange attractors. The behavior of such particles differs significantly from the patterns in the fluid flow driving the dynamical system. This may have implications for transport, mixing, and separation in multiphase flows as well as in predicting the dispersion of trace substances in natural fluid media. Numerical results suggest that the sensitivity of the limit sets to parameter values may be used to separate species of particles differing slightly in the value of some physical property.