中文摘要：

对流量周期性变化时的阻力特性进行了实验研究及数值分析。实验结果表明,流量波动时阻力变化与流量变化具有相同的周期,但流量的变化相对于压降变化存在一个相位差,且在层流时的相位差明显大于紊流时;通过特征线法（MOC）对与实验相同流动条件时的流动特性进行数值计算,得到了与实验相同的结论。

英文摘要：

The experimental and numerical studies on the flow resistance characteristics under flow fluc-tuating conditions in a circular channel are carried out.The experimental results show that the pressure drop fluctuates with the same period of fluctuating flow rate;however,there is a phase lag between the two,and the phase lag in laminar flow is bigger than that in turbulent flow.In addition,the flow characteristics under the experiment conditions are numerically simulated based on the method of characteristic（MOC）.The simu-lation results are in agreement with experimental values.