微管中非混溶两种流体运动界面的特征

以平流泵为压力源,在不同管径的石英微管中进行流动试验,显微镜观察和拍摄水-气界面和油-水界面,在微米尺度下进行了不同流速的运动界面实验,研究了微管中非混溶两种流体运动界面的特征,以及润湿性对流体在微管中流动界面的影响.实验中观察到了润湿界面的滞后现象,即界面随流速的不同而改变的现象.实验结果表明:水在微管中流动的气液界面随着流速的不同形状发生改变,流速较小时,界面基本保持为凹液面;随着流速的增加,液面由凹液面向平液面发展,进而发展为凸液面.在表面张力的作用下,微管的尺寸越小,两种流体的性质差别越大,界面的润湿滞后现象越不明显,讨论了界面和润湿滞后存在的问题和可能的应用.

Movable Interface Between Two Fluids in Quartz Micro-channels

The characteristics of two liquids interface in micro channels and the influence of wettability were investigated by flow experiments in different micro channels with diameter of 75μm, 250μm and 1mm respectively, and deionized water and silicon oil were selected in this experiment. The pump was used as a pressure source, and the pictures of movable two-phase interface were observed and screened with microscopes. Some experiments were carried out at different velocity and with liquid-gas interface and water-oil interface. The phenomena of wettability hysteresis were observed. The results indicate that the styles of liquid-gas interface and water-oil interface changes with different flow velocity, which changes from concave to even until convex with the increasing velocity. The figure of interface changes more difficultly in smaller micro channels due to the surface tension. The possible prospects of two-phase interface and wettability hysteresis were discussed.