The interfacial shear stress and liquid film thickness are very important to establish the basic model of annular flow in practical applications. In this paper, the liquid film thickness of annular flow in a narrow vertical rectangular channel with a cross-sectional area of 70 mm × 2 mm was measured based on the PCB liquid film sensor. According to the experimental results, the average liquid film thickness, base film thickness and interfacial friction factor were calculated and analyzed. The experimental results showed that the liquid film thickness was affected by the gas phase velocity and the liquid phase velocity, but the effect of the gas phase velocity on the liquid film thickness decreased gradually with increasing gas phase velocity. Moreover, the interfacial friction factor was obvious affected by the liquid phase velocity at low gas phase velocity, but this influence gradually decreased with increasing gas phase velocity. Existing correlations for above parameters were summarized and evaluated with the current data, and there was a large deviation between the predicted results and the experimental results. Therefore, a new correlation for above parameters was proposed, respectively.

界面剪切应力和液膜厚度对于建立实际应用中的环流基本模型非常重要。本文基于PCB液膜传感器测量了横截面积为70 mm×2 mm的狭窄垂直矩形通道中环形流的液膜厚度。根据实验结果，计算分析了平均液膜厚度、基膜厚度和界面摩擦系数。实验结果表明，液膜厚度受气相速度和液相速度的影响，但随着气相速度的增加，气相速度对液膜厚度的影响逐渐减小。而且，界面摩擦系数在低气相速度时受液相速度的影响明显，但随着气相速度的增加，这种影响逐渐减小。上述参数的现有相关性是用当前数据进行总结和评估的，预测结果与实验结果存在较大偏差。因此，分别针对上述参数提出了新的相关性。