Left Panel: Fluidization by lift of 3000 spherical particles placed in a Poisuille flow (planar cut is shown). Top panel shows the spherical particles, bottom panel shows out-of-plane vorticity. Note that the particles go in and out of the symmetry plane indicating three-dimensional nature of the fluidization process.

Right Panel: Interaction of a light-than-fluid spherical particle with a stationary Gaussian vortex. The density ratio between the fluid and particle is 1000:1. Also shown are iso-surface of vorticity behind the particle.