水平管降膜冷态流动形态及滞后现象实验研究

Study on cold-flow patterns and hysteresis of falling film on a horizontal pipe

中文关键词: 降膜流动  流动形态  滞后现象  泰勒波长

英文关键词: falling film flow  flow pattern  hysteresis  Taylor wavelength

中文摘要:

      以25.00 mm铝黄铜管水平管外降膜流动过程为研究对象,对以水为工质的管间流动形态及管间距对临界雷诺数的影响进行研究,基于观察到的流动形态变化的五个阶段分析了流型转换的滞后现象。计算了泰勒波长理论值并与实验测量值进行对比分析。研究结果表示,流动形态的五个阶段,临界雷诺数随管间距增大而增大,滞后现象存在于各个临界流态转化点中,柱帘-帘阶段滞后区间最大,实验泰勒波长较理论值略低,且在理论值附近波动。

英文摘要:

      The falling film flow process outside the horizontal pipe of 25.00 mm aluminum brass tube is taken as the research object, the effect of the flow pattern between the tubes using water as the working medium and the distance between the tubes on the critical Reynolds number is analyzed, Based on the observed five stages of the flow pattern change, the hysteresis of the flow pattern transformation is analyzed. The theoretical value of Taylor wavelength is calculated and compare with the experimental measurement value. The results show that the critical Reynolds number increases with the increase of tube spacing and hysteresis exists in each critical flow pattern transformation point. The column curtain stage has the largest lag interval the experimental, Taylor wavelength is slightly lower than the theoretical value, and fluctuates around the theoretical value.