Experimental study of a drop bouncing on a wall in a liquid

The behavior of millimetric drops rising in water and bouncing under a horizontal plate is studied using a high-speed video camera. The position and velocity of the center of mass of the drops, as well as their deformation are analyzed. The bouncing is found to be very dissipative, almost 80% of the energy being lost during the interaction with the wall. The deformation of the drop is governed by the balance between its inertia and capillary effects and evolve like a dissipative mass-spring system. The coefficient of restitution is compared to previous experiments done for drops in air, bubbles in water as well as solid spheres in various fluids. (c) 2005 American Institute of Physics.