高聚物熔滴形成与断裂过程的数值模拟

为了探究高黏度流体在机械撞针式微液滴喷射头作用下形成液滴及断裂的过程，采用计算流体力学软件模拟了聚丙烯熔滴的形成过程。结果表明，熔滴形成时要经历颈缩、伸长及断裂等过程，在各种力的综合作用下形成拖尾状液滴，与低黏度液滴在形态上存在显著差异。另外还分析了锥面张角、熔腔间隙、喷孔直径及喷孔长度对熔滴体积的影响，从而为微喷头的结构设计提供参考。

Numerical simulation of the formation and fracture process in polymer droplets

In order to investigate the formation and fracture process in high-viscosity fluid droplets in a mechanical jet, computational fluid dynamics software was adopted to simulate the formation of polypropylene droplets. The results show that behavior such as necking, extension, and fractionation occurred during the formation of a polymer droplet. The resulting droplet has a long tail because of the combination of forces and shows significant differences in shape when compared with a low-viscosity droplet. In addition, the effect of varying the cone angle, chamber gap, orifice diameter and orifice length on the droplet volume was analyzed. The results of this study provide a reference for the structural design of mechanical jets.