Effect of the confinement on the properties of ultrasonic vibrated granular gases
The properties of a ultrasonic vibrated granular gas are investigated by using an event-driven Molecular Dynamics simulation of inelastic hard spheres that are fluidized by a vibrating bottom wall (sonotrode) in boxes with different geometries showing either no or an increased confinement. It appears that geometry controls dramatically not only the distribution of wall impacts and their velocity and impact angles, but also more fundamental properties of the granular gas such as temperature and density. For geometries displaying an acute angle (prism), stacking is found, which induces a strong temperature and density gradient. The underlying origin of such phenomena for the granular gas arises from the spatial limitation, confinement, combined with the inelastic collisions induced by closely located side walls. It underscores the possibility that kinetic and thermodynamic properties of granular gases can be changed by simple geometries inducing spatial limitation. Â© 2013 Springer-Verlag Berlin Heidelberg.