Abstract:

On the basis of simulating the phase field method of dendritic growth, this work combined the multi-relaxation format of lattice Boltzmann method of the phase field method, established the phase field-lattice dynamic coupling model, and numerically simulated the microstructure of dendrite growth occurred in the process of polymer crystallization. This coupling model circumvented difficulties of traditional phase field method that needed resolve solid liquid interface accurately in high resolution which would severely impact the option of time steps. Using lattice Boltzmann method (LBM), this work came up the adaptive time stepping, that allowed changing time step expect sizing grid correspondingly, in other words, time step can be large, however, the results of numerical simulation will not emerge the phenomenon of dispersion, avoid the using of high precision differential formats. Using FORTRAN to accomplish the coupling model's establishment and simulating the crystallization of isotactic polystyrene, this work researched the crystallization of isotactic polystyrene at different experimental temperature, and compared the simulated results with the reality experimental results, to determine the feasibility of the coupling model.