Modelling the normal bouncing dynamics of spheres in a viscous fluid

Edouard Izard (1) , Laurent Lacaze (2) , Thomas Bonometti (2)

1 ArcelorMittal Maizières Research SA
2 IMFT - Institut de mécanique des fluides de Toulouse

Bouncing motions of spheres in a viscous fluid are numerically investigated by an immersed boundary method to resolve the fluid flow around solids which is combined to a discrete element method for the particles motion and contact resolution. Two well-known configurations of bouncing are considered: the normal bouncing of a sphere on a wall in a viscous fluid and a normal particle-particle bouncing in a fluid. Previous experiments have shown the effective restitution coefficient to be a function of a single parameter, namely the Stokes number which compares the inertia of the solid particle with the fluid viscous dissipation. The present simulations show a good agreement with experimental observations for the whole range of investigated parameters. However, a new definition of the coefficient of restitution presented here shows a dependence on the Stokes number as in previous works but, in addition, on the fluid to particle density ratio. It allows to identify the viscous, inertial and dry regimes as found in experiments of immersed granular avalanches of Courrech du Pont et al. Phys. Rev. Lett. 90, 044301 (2003), e.g. in a multi-particle configuration.

Mots clés: Bouncing spheres; IBM; DEM

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

Edouard Izard, Laurent Lacaze, Thomas Bonometti. Modelling the normal bouncing dynamics of spheres in a viscous fluid. Powders and Grains 2017 – 8th International Conference on Micromechanics on Granular Media, Jul 2017, Montpellier, France. pp. 1-4, ⟨10.1051/epjconf/201714009014⟩. ⟨hal-01757874⟩