中文摘要：

对摇摆状态下，3种不同管径（15，25，34．5mm）的光滑有机玻璃管管内单相水的摩擦压降特性进行分析．与传统的稳定状态下的经验公式值进行对比。发现摇摆状态下的摩阻系数随时间变化有明显的周期性，而且远远大于传统经验公式计算值．通过对摇摆状态下单相水的运动分析，并在结合实验数据以及综合考虑各影响因素的基础上，给出了摇摆状态下摩阻系数的计算关系式，与传统的Blasius和Niklaus经验公式相比，计算值与实验值符合较好．

英文摘要：

The pressure drop＇s characteristics of single-phase water flowing though vertical rolling pipes are analyzed. The test section was smooth glass tubes, with the inside diameters of 15, 25, and 34.5 mm respectively. Compared with the traditional empirical equation values under stable condition, the frictional factor in rolling pipes obviously shows periodic variation, and its average value is bigger than the traditional empirical equation values. According to the analysis of the motion of single-phase water in vertical roll ing tubes, the correlation of calculating the frictional factor under rolling condition is proposed. Compared with the values of Blasius or Niklaus empirical equation, the predictions agree well with the experimental data.