单螺杆挤出机中非牛顿流体层流混合停留时间表征

Characterization of Residence Time of Laminar Mixing of Non-newtonian Fluid in Single Screw Extruder

基于有限差分数值模拟技术,提出了计算非牛顿流体在单螺杆挤出机内停留时间分布的半解析方法,得到了不同操作参数下的停留时间分布,该分布可用来表征聚合物熔体在加工过程中的混合情况。结果表明:半解析方法能够反映由流体的非牛顿性所导致的耦合流场及压力反流对混合的影响,能更真实地反映聚合物熔体在单螺杆挤出机内的混合程度。

Based on finite difference method of numerical simulation, the semi-analytical method is proposed in the paper, which is adapted to compute the residence time distribution（RTD） of polymer melt in a single screw extruder, then the RTD under different operation parameters are obtained to characterized the mixing of polymer melt in the course of processing. The effect of coupling flow field and pressure backflow on mixing can be shown by the method proposed in the paper, and the mixing degree of polymer melt in the single screw extruder is exposed more realistically.