Measurements of the coefficient of restitution for particle collisions with ductile surfaces in a liquid

This paper presents the approach and rebound of a particle colliding with a deformable surface in a viscous liquid. The complex interaction between the fluid and the solid phases is coupled through the dynamics of the flow as well as the deformation process. For the experiments, steel particles impacted ductile aluminum alloys samples immersed in an aqueous mixture of glycerol and water. The experiments involved particle Stokes number from 5 to 10^5 and deformation parameters from 10^(−2) to 10^2. From the experiments, the coefficient of restitution is shown to depend on both these parameters. The coefficient of restitution is closest to unity when the deformation parameter is less than one and the Stokes number is greater than 10^3. The coefficient of restitution decreases as the deformation parameter increases and when the Stokes number decreases