A falling cloud of particles at a small but finite Reynolds number

Florent Pignatel (1) , Maxime Nicolas (1) , Elisabeth Guazzelli (1)

1 IUSTI - Institut universitaire des systèmes thermiques industriels

Through a comparison between experiments and numerical simulations, we have examined the dynamics of a cloud of spheres at a small but finite Reynolds number. The cloud is seen to flatten and to transition into a torus, which further widens and eventually breaks up into droplets. While this behaviour bears some similarity to that observed at zero inertia, the underlying physical mechanisms differ. Moreover, the evolution of the cloud deformation is accelerated as inertia is increased. Two inertial regimes in which macro-scale inertia and micro-scale inertia become successively dominant are clearly identified.

Mots clés: breakup/coalescence; particle/fluid flow; suspensions

Domaines: Mécanique des fluides [physics.class-ph]

Florent Pignatel, Maxime Nicolas, Elisabeth Guazzelli. A falling cloud of particles at a small but finite Reynolds number. Journal of Fluid Mechanics, 2011, ⟨10.1017/S0022112010005501⟩. ⟨hal-01432973⟩