矩形微通道内弹状流流动特性

Flow Characteristics of a Slug Flow Inside a Rectangular Microchannel

以空气为气相介质,以不同表面张力的液体为液相介质,利用可视化技术对矩形截面为100μm×800μm的微通道内弹状流气柱速度、气柱长度、截面含气率、气柱产生频率进行了测量。通过实验发现气柱速度受C0(流动参数)影响,流动参数随着表面张力的增加而减小。根据Qian等人提出的关联式,提出了新的预测气柱长度模型,预测值与测量值算值相比较,平均偏差为14.6%。Ali等人提出的关联式预测截面含气率效果最好。气柱产生频率受两相表观速度和液体表面张力影响。

With air serving as the gas phase medium and a liquid having various surface tensions as the liquid-phase medium, measured by using the visualization technology were the air column speed,air column length,void fraction in a section and air column production frequency of a slug flow inside a microchannel having a rectangular section of 100μm × 800μm. It has been found during the test that C 0 （a flow parameter） will have an effect on the air column speed while the flow parameters will decrease with an increase of the surface tension. According to the correlation formulae proposed by Qian and others,a new model for predicting the air column length was presented. The average deviation between the predicted value and the measured one is 14. 6% when compared. To use the correlation formulae proposed by Ali and others to predict the void fraction in a section can achieve the best effectiveness. The air column production frequency will be influenced by the apparent speed of both phases and the surface tension of the liquid.