CLUSTERS OF PARTICLES
FALLING IN A VISCOUS FLUID WITH PERIODIC BOUNDARY CONDITIONS

M. L. Ekiel-Jeżewska and B. U. Felderhof

Phys. Fluids**18**, 121502 (2006)

M. L. Ekiel-Jeżewska and B. U. Felderhof

Phys. Fluids

Three identical point particles falling under gravity in a viscous fluid with periodic boundary conditions. Stable (top) and unstable (down) solutions of the equations of Stokesian dynamics are shown for two initial configurations: horizontal equilateral triangles with side lengths d=0.42 and d=0.43 close to a critical size d=0.4242. Four periodic cubic cells of unit length are visible in each window. The frame of reference is moving with the time-averaged velocity of the red and blue particles.

Transition from periodic to irregular motion,
caused
by an extremely small numerical perturbation

(d=0.43, front view).

(d=0.43, front view).

See also: M. L. Ekiel-Jeżewska and B. U. Felderhof,