Abstract: Bubbly flow widely exists in a variety of chemical reaction equipment, so researching the effect of periodic force on frictional characteristics of bubbly flow in rectangular channel can support the experimental basis for studying flow characteristics under unstable state.Experiment was carried out under normal condition,and the rolling condition was set at 5?-8 s,10?-8 s,15?-8 s,15?-12 s and 15?-16 s.The experimental results showed that frictional pressure drop fluctuated periodically with rolling period and friction factor was several times of that under steady state.The fluctuation amplitude of frictional pressure drop increased with the decrease of rolling period and the increase of rolling angle.The more violent the rolling, the greater the fluctuation amplitude, while, on the contrary, the increase of flow velocity would weaken the fluctuation.Influence coefficient(ratio of rolling friction factor to steady state one) is defined to express the effect of periodic force, and an empirical correlation for influence coefficient was obtained.

Key words: periodic force, rectangular channel, bubbly flow, influence coefficient, friction factor

摘要： 泡状流广泛存在于各种化工反应设备中,研究周期惯性力影响下矩形通道泡状流的阻力特性,可以为研究非稳态条件下的流动特性提供实验支持。本实验在常温常压条件下进行,摇摆工况选定为5°-8 s、10°-8 s、15°-8 s、15°-12 s和15°-16 s,实验结果表明摇摆条件下瞬态摩擦压降的变化具有明显的周期性,两相平均阻力系数是稳态摩阻系数的几倍到十几倍,随着两相Reynolds数的变大,瞬态摩阻系数的波动幅度和平均水平均变小;摇摆周期越小,摇摆振幅越大,即摇摆运动越剧烈,摩擦压降的波动幅度也越大;定义了周期惯性力的影响系数(摇摆条件与竖直条件下摩阻系数的比值),利用量纲分析和多元拟合方式得到关于影响系数的经验关系式,预测值与实验值符合程度较好。

关键词: 周期惯性力, 矩形通道, 泡状流, 影响系数, 摩阻系数