矩形微通道内气体-互溶混合液体两相流流型的实验研究

Experimental Investigation on Two-Phase Flow Patterns of Gas-Miscible Liquids in Rectangular Microchannels

在包含了"十"字形和"T"形结构的微通道系统内,以氮气、丙酮(或乙醇)及质量分率0.5%表面活性剂poloxamer188的水溶液为实验介质,在气相表观速度为0.004～2.191 m/s,水溶液表观速度为0.056～0.281 m/s,溶剂(丙酮或乙醇)表观速度为0.017～0.086 m/s时,利用可视化观察与压力波动观察相结合的方法,观察到了毛细管泡状流、弹状流、溪流和扰动流四种流型,其中毛细管泡状流、溪流为微通道内所特有的流型。通过与文献报道的流型进行对比,发现实验的流型出现了一些新的特征。应用不同的压降模型对不同流型的摩擦压降数据进行了关联,发现当Chisholm模型参数C值为2.81时,可得到最佳的关联结果。

Nitrogen gas, acetone （or ethanol） and a aqueous solution with mass fraction 0.5% poloxamer 188 were used as working fluids to investigate the behaviors of two-phase flow patterns in a rectangular microcharmel. Within the superficial velocities of the gas of 0.056-0.281 m/s, the superficial velocities of the aqueous surfactant solution and the solvent of 0.004-2.191 m/s and 0.017-0.086 m/s respectively, several flow regimes such as the capillary bubble flow, the slug flow, the rivulet and the chum flow were observed by combining the visualization and pressure drop pulsation methods in the present microchannel, Among them, the capillary bubble flow and the rivulet were typically special flow patterns in microchannels, which were found to have some interest characteristics. Different two-phase frictional pressure drop models were employed to correlate the experimental data of different flow patterns. The results showed that Chisholm model with parameter C of 2.81 has the best prediction compared with the experimental data.