Numerical simulation of spherulite and shish-kebab growth for semi-crystalline polymer melts via phase-field model

Polymer crystallization is an important research topic in materials sciences. The phase field model is employed to simulate the growth of spherulites and shish-kebabs for the semi-crystalline polymer under melt flows. Firstly, the phase field equation is discretized by the finite difference method(FDM), the energy equation is solved by the finite volume method(FVM), and the governing equation of viscous polymer melts is modeled and solved by the lattice Boltzmann method(LBM). And then the numerical simulations are conducted for the growth process of spherulites and shish-kebabs under the static and flowing conditions, respectively. Morever, the growth of shish-kebabs are simulated in two different mold cavities under melt flows and compared with each other. Finally, the growth of co-existed spherulites and shish-kebabs are simulated in both static and flowing states. Numerical results show that the coupled FD-FV-LB algorithm could successfully capture the growth interfaces of spherulites and shish-kebabs. The complex cavity makes the flow more complex, thereby changing the crystal morphologies. The melt flow makes the polymer crystals grow faster and densely towards the upstream direction, and increase the temperatures of the crystals.