弹性/黏弹性混合管道瞬变流参数校核方法

为探究弹性管道与粘弹性管道串联混合连接的管道系统瞬变流压力波动的影响规律，设计并搭建了弹性/粘弹性串联混合管道系统瞬变流实验台，分别是镀锌钢管、镀锌钢管与聚丙烯（polypropylene,简称PPR）管混合管和镀锌钢管与聚乙烯（polyethylene,简称PE）管混合管。在不同初始流量情况下，分别对三种管道系统进行了瞬变流实验，基于实验数据，对粘弹性管道瞬变流模型结合一维拟稳态摩阻模型的参数进行校核，并提出了混合管道瞬变流参数校核方法。结果表明：使用粘弹性管道替换部分弹性管道会使得瞬变流压力波峰值衰减幅度下降，钢管/PPR混合管道相比钢管/PE混合管道具有更大的下降幅度。改变初始流量不会引起压力波相位发生改变，其对粘弹性效应产生的影响可以忽略不计。此外，应用一维拟稳态摩阻模型可以较准确地模拟混合管道瞬变流的压力波动过程，本文所提出的混合管道瞬变流参数校核方法可简便且准确地校核混合管道瞬变流参数，为工程中混合管道瞬变流的数值计算提供参考依据。

A parameter calibration method of transient flows in elastic/viscoelastic mixed pipes

To explore the influence mechanism of transient flow pressure fluctuation in the pipeline system with a mixed connection of elastic pipe and viscoelastic pipe in series, a transient flow test rig of elastic/viscoelastic series mixed pipe system was designed and constructed, including galvanized steel pipe system, galvanized steel/polypropylene pipe mixed pipe system, and galvanized steel/polyethylene pipe mixed pipe system. The transient flow experiments were carried out on three kinds of pipeline systems at different initial flow conditions. Based on the experimental data, the parameters of the transient flow model of viscoelastic pipes combined with one-dimensional quasi-steady friction model are calibrated, and a method of calibrating transient flow parameters in mixed pipelines is proposed. The results show that replacing part of elastic pipe with viscoelastic pipe can reduce the peak value of transient pressure fluctuation, and the steel tube /PPR mixed pipe has a greater decline than the steel tube /PE mixed pipe. Changing the initial flow rate will not change the phase of the pressure fluctuation, and its influence on the viscoelastic effect can be neglected. In addition, the one-dimensional quasi-steady friction model can simulate accurately the pressure fluctuation of mixed pipes. The method proposed in this paper can be used to calibrate the transient flow parameters of the mixed pipes easily and accurately, which provides a certain reference for the numerical calculation of transient flow in the mixed pipeline in engineering.