直角管道支化聚合物流动的数值模拟及粘弹分析

The Numerical Study of Viscoelastic Flows Through a Right-Angle Duct with Inset

选取基于Doi-Edwards模型发展起来的XPP模型作为本构方程,采用耦合稳定化技术的同位网格有限体积法模拟了直角管道流以及嵌件直角管道流。给出了直角管道流和嵌件直角管道流中表征聚合物宏观信息量的等值线图,分析了流变参数以及嵌件对管道截面上表征聚合物宏观信息量的影响。数值结果表明,XPP模型能够合理描述聚合物溶液浓厚体系的粘弹效应,其模型中流变参数的变化能够预测聚合物溶液拉伸属性及法向应力差的基本特征。同时,流道中嵌件的放置将使得聚合物宏观属性的变化趋势在嵌件附近发生质的变化。

In this study, the finite volume method in the non-staggered grid is used to simulate the branched polymer melt through a right-angle duct and right-angle duct with inset. The constitutive equation follows the extended pom-pom model, which is developed from Doi-Edwards model based on the rheology molecular theory. The viscoelasticity of the sections in right-angle duct were predicted here by the contour figures of the stream function, the backbone stretch, the first normal stress difference and the second normal stress difference. Moreover, the influence of inset on viscoelasticity of the sections in right-angle duct was alto discussed in detail. The numerical result indicates that the essential characteristics of elongation behaviors and normal stress difference can be described precisely as the various model parameters vary, In our simulations, it is easy to be seen that the viscoelasticity of polymer melt changes obviously under the effect of inset.