Study On The Aggregation And Breakup Of Fractal Clusters Through Computer Simulation

At present,many contributions have been gained on the study of the aggregation of clusters,and a number of theoretical models on aggregation have been put forward.Furthermore,some researchers have designed simulation programs to realize these by computer.However,most traditional programs' architectures on aggregation models are mostly procedure-oriented,which faces a series of problems: 1)With the increment of new algorithmic logics,maintenance and improvement even extension on the program will turn into impossibility,and its disadvantages will become more prominent;2)The running process of traditional simulation programs are transparent for users,which haven't reached a better interaction;3)Some redundant execution steps exist in traditional programs,such as unnecessary loops and judgments,wasting a large amount of CPU time when simulating on computer;4)Data structures still have potential defects,which need further optimization.Currently,theories about aggregation have tended to become mature,but few people have taken the opposite process,breakup,into account,and the relevant theoretical models are rare.As for some issues such as How to quantify the stability of one cluster,Whether one cluster will disperse into small structures under some significant factors,Which position is unsubstantial in a cluster,What will happen when a cluster collapses,and How many small structures will be generated when one cluster collapses.All these questions above haven't been answered perfectly.So,it is necessary to build up a breakup model for further investigations.In order to explore and solve above issues,the main works and contributions are as follows:(1)An aggregation model was constructed based on on-lattice,and two aspects were mainly considered: one is the movement of clusters;the other is collision among clusters.The previous traditional program was reconstructed by Java,which is a kind of object-oriented programming language,and Java3D-technology,which is applied to present current status.In addition,given the defects of traditional algorithms,the program is optimized in order to achieve better time-efficiency.The reconstructed program reaches excellent readability and expansibility,and enables the user-interface to realize a good visual experience.Comparing with old algorithms,the optimized algorithm gets an obvious progress on execution efficiency.(2)To explore the breakup of clusters,a model called "Bisection" is proposed,and On-lattice pattern is also used to construct a unified model.In addition,the model mainly considers two significant aspects——division and the diffusion.Hence,Java and Java3D-technology are used to develop a simulation program to mimic the breakup.The results indicate that "Bisection" not only can well describe the explosive breakup,but also facilitate clusters' breakup in a serializable way.(3)A compound model which combines the aggregation and breakup under the same system is provided,and the model is applied to mimic the evolvement of colloid system.The simulation process not only considers the aggregation among colloidal particles(or clusters),but also the breakup of unstable colloidal clusters.Finally,aggregation and breakup will gradually reach a dynamic balance,which is close to the actual colloidal system.