A comparison of pendulum experiments and discrete-element simulations of
oblique collisions of wet spheres
Abstract
Oblique collisions of two spherical particles coated with a thin layer
of viscous liquid are considered. Experimental measurements are
performed using particle tracking velocimetry. Comprehensive
experimental data for collisions with an impact angle between 0° - 60°
are presented. Collisions are characterised by the Stokes’ number, the
coefficient of restitution, and the rotational velocity. The experiments
are compared to numerical simulations using the discrete element method
(DEM). The translational velocities predicted by the simulations were in
good agreement with the experiments at high Stokes’ number, where the
models are dominated by the normal components. As the tangential forces
become more significant (i.e. at low to medium Stokes’ number, and high
collision angle), agreement between the simulations and experiments is
poorer. At low Stokes’ number the translational velocities were in good
agreement with the experiments, but was poorer at high Stokes’ number.