复乳液在延展流中流变行为研究

Rheological Behaviors Investigation of Multiple-Emulsion Globules in Extensional Flows

为了探究复乳液内部子液滴的大小和位置分布对其流变行为的影响,采用二维波谱边界元素法数值模拟了延展流中同心复乳液和非对称复乳液的流变行为.通过改变子液滴的大小和位置得到复乳液不同的流变行为,并深入分析其变形和移动机理.研究结果表明:在不同的毛细管数下,同心复乳液内部子液滴的存在对复乳液的变形有正反双重作用;双子液滴的不对称分布导致非对称复乳液两侧界面变形和曲率不对称,界面曲率差驱使母液滴在延展流中发生移动.

In order to explore the impact of inner droplets’size and position on rheological behaviors of outer droplets,the two-dimensional spectral boundary element method was employed to simulate the rheological behaviors of concentric multiple-emulsion globules and asymmetric multiple-emulsion globules in extensional flows.The different rheological behaviors of multiple-emulsion globules were obtained by changing the size and position of the inner droplets,and the mechanism of deformation and movement was deeply analyzed.The results show that the inner droplet of the concentric multiple-emulsion globules has positive or negative effects on the deformation of the globules under different capillary numbers.The asymmetric layout of the double-emulsion droplets leads to the asymmetric deformation of the globules with different interface curvatures,which causes the oriented shift of the globules.