聚合物加工过程中，结晶性聚合物熔体将经历从流动到结晶的转变，流动诱导结晶行为是影响制品结晶形态并决定制品性能的关键因素，然而流动诱导结晶的机理尚不十分清楚。本项目基于耦合相场-有限体积-格子玻尔兹曼方法，对流动诱导聚合物结晶行为进行多尺度建模和计算研究。首先，采用浸入边界-有限体积法求解粘弹性流体控制方程，实现聚合物宏观流动的数值模拟。其次，采用相场-浸入边界-格子玻尔兹曼方法模拟介观流动诱导结晶生长，并给出相应的误差分析和精度检验。最后, 通过物性参数实现宏-介观尺度的耦合，探析宏观流动对介观结晶行为的影响机理。本项目的实施不仅可以丰富和加深对流动诱导结晶机理的认识，而且可以为聚合物结晶行为提供新的计算模型和模拟方案。

In the polymer processing process, the melt of crystalline polymer undergoes a transition from flow to crystallization. The flow-induced crystallization behavior is a key factor affecting the crystallization morphology and properties of products, but the mechanism of flow-induced crystallization is not very clear. In this project based on the coupled phase field-finite volume-lattice Boltzmann method, we will conduct the multi-scale modeling and computational research on the behavior for flow-induced polymer crystallization. Firstly, the immersed boundary-finite volume method is used to solve the governing equation for viscoelastic fluid and the polymer macroscopic flow is numerically simulated. Secondly, the phase field-immersed boundary-lattice Boltzmann method is used to simulate mesoscopic flow-induced crystallization growth, and the corresponding error analysis and accuracy test are provided. Finally, the macro-mesoscopic scale coupling will be realized by physical parameters, and the influence mechanism of macroscopic flow on mesoscopic crystallization behavior will be analyzed. The implementation of this project can not only enrich and deepen the understanding of the mechanism for flow-induced crystallization, but also provide the new numerical model and simulation programme for polymer crystallization behavior.