矩形通道高宽比对两相流动阻力和流型关系的影响

在可视化观察的基础上，实验研究了矩形通道高宽比对两相流动阻力和流型关系的影响。实验选择了3种通道尺寸的实验段，截面宽度相同，全部为43 mm，高度分别为1.41、3和10 mm，根据受限因子C_o，前两个实验段属于窄通道，第3个属于常规通道。实验结果表明：高宽比不同时，随着气相流速的增加，通道内两相流动压降呈不同的变化趋势。对于10 mm通道，低气相流量时重位压降占主要成分，而对于1.41 mm和3 mm通道，摩擦压降占主要成分；随着气相流量的增大，总压降中摩擦压降的比例也增大；对于10 mm矩形通道，可利用压降变化规律确定搅混流的发生范围。

Effect of Aspect Ratio on Relationship Between Flow Resistance and Flow Regime of Two-phase Flow in Rectangular Channel

On the basis of visual observation, the effects of aspect ratio on relationship between flow resistance and flow regime were investigated experimentally for two-phase flow in three rectangular channels with the same cross-section width of 43 mm and different heights of 1.41, 3 and 10 mm, respectively. According to the criteria in terms of restriction factor C_o, the former two channels belong to narrow channel, whereas the last one is conventional channel. The experimental results show that the two-phase pressure drops in rectangular channel with different aspect ratios have different variation trends with the increase of the gas velocity. For the 10 mm channel, the gravitational pressure drop makes the major percentage of total pressure drop at low gas velocity while the frictional pressure drop is dominant for the 1.41 mm and 3 mm channels. With the increase of the gas flow rate, the frictional pressure drop contributes more to total pressure drop. The range of churn flow can be distinguished from its pressure drop characteristic in 10 mm channel.