화학공학소재연구정보센터
Journal of Non-Newtonian Fluid Mechanics, Vol.229, 79-85, 2016
Topological transitions in unconfined vibrated concentrated suspensions
Vertical vibration of a concentrated suspension of spherical particles in a liquid yields an array of intriguing behaviors. Here we report new results for unconfined suspensions on a vibrating plate, and show that under certain conditions the suspension forms depressions or craters, while in other conditions it gathers to form a mound, a conical "volcano", or even a sphere that sits just above the vibrating plate. This behavior results from a jamming transition as the plate accelerates upward, followed by unjamming as it accelerates downward. The ability of periodic jamming and unjamming to induce topological transitions is confirmed by scaling analysis, and sphere formation is further examined by numerical simulation of a suspension with an acceleration-dependent viscosity. (C) 2016 Published by Elsevier B.V.