This experimental study reveals a counterflow slip at the interface of two immiscible fluids filling a sealed vertical cylindrical container whose bottom disk rotates while other walls are stationary. An advanced particle image velocimetry helps us analyze and quantify streamline patterns and velocity profiles of the steady axisymmetric flows of both fluids. As the angular velocity of a disk increases, starting from zero, three changes occur in topology of the upper-fluid flow while topology of the lower-fluid flow remains invariant. These changes result in the counterflow slip at the entire interface, whose nature is speculatively discussed and requires further research.

中文翻译：

---

双流体漩涡中的逆流滑移

该实验研究揭示了两种不混溶流体在填充密封垂直圆柱形容器的界面处的逆流滑动，该容器的底部圆盘旋转而其他壁静止。先进的粒子图像测速仪帮助我们分析和量化两种流体稳定轴对称流动的流线模式和速度剖面。随着圆盘角速度的增加，从零开始，上部流体流动的拓扑结构发生三个变化，而下部流体流动的拓扑结构保持不变。这些变化导致整个界面的逆流滑移，其性质是推测性的，需要进一步研究。