Dynamic Behavior Of A Vibrofluidized Granular Gas In N Connected Compartments

In this thesis,we use experiments and numerical simulation to research the dynamic behavior of a vibrofluidized granular gas in N connected compartments.In experiment,we firstly extend two-connected compartmentalized system to N-compartment system,and discuss the dynamic behavior of a binary granular mixture in two kinds of systems respectively(one system is cyclic and the other is non-cyclic).The rules of cyclic oscillation in these systems are found to be different in experiment.For a non-cyclic system,the order and interval of the clustering in a linear configuration are invariable.The particles always cluster periodically in one of the N compartments in a tactic order.The mean interval time of the clustering transition from the aside to the middle is two times of the one with opposite clustering direction.But for a cyclic system,the binary gas clusters cyclically into one of the compartments in a random order and the interval of the clustering transition has a tendency to decrease with evolution of time and tends to a constant value.In addition,in a certain transition range a remarkable intermittent clustering behavior is observed at first in our experiment,i.e.the granular gas undergoing a cyclic oscillation shows a sudden uniform state and keeps it for a long time until the new cyclic cluster state emerges.In numerical simulation,we apply the event driven method to simulate evolution of granular gas in N connected compartmentalized systems(N=2,3,4),and make three dynamic behaviors found in experiments recur.Three dynamic behaviors are stationary asymmetric segregated state,periodic one and stationary homogeneous one.The effect of granular parameters such as mass radios of two kinds of granulars,diameter ratios,granular number,restitution coeffictients and the length of compartment on oscillation regime and clustering amplitude are investigated in detailed.The rules of dynamic characteristics of system associated with these parameters are presented.The clustering amplitude varies with the increase of applied intensity in Boltzmann function,which is found firstly.It is different from experiments results that the oscillation cyclic periods obtained in numerical simulation are random and the order of clustering in three or four compartments system is variable.The mean interval time in each compartment is proportional to (f-f₀)^-a,where f denotes the applied frequency and f₀ is a transitional value between periodic state and stationary asymmetric segregated state.Especially, stationary cyclic oscillation phenomenon is firstly found in a compartalized granular system only composed with one kind of particles.