管道中滞留气团排放过程的二维数值模拟研究

A 2-D Numerical Simulation Study on the Process of Air Mass Emission in Pipeline

摘要: 在极端暴雨条件下，城市雨洪排水管道中常会发生含滞留气团的瞬变流动。针对有压水流作用下滞留气团运动、排放的动态过程，本文采用VOF (Volume of Fluid Model)模型和k-ε湍流模型进行了二维数值建模和计算，并将模拟结果与已有实验观测结果进行对比分析。结果表明：VOF模型模拟出的滞留气团的运动过程、瞬态压力变化结果均与实验结果吻合。同时，对二维模拟时，主支管连接中可能存在的“等截面比例”和“等管径比例”两种简化方法进行了比较分析，比较结果表明，“等截面比例”方法计算的压力结果更接近实验值。

Abstract: Under severe rainstorm conditions, transient flow of trapped air masses often occurs in urban storm water drainage pipelines. In this paper, VOF (Volume of Fluid Model) model and k-ε turbu-lence model are used to simulate and calculate the dynamic process of the movement and emission of the stranded gas mass under the action of pressure flow. The simulation results are compared with the experimental results. The results show that the motion process and transient pressure variation of the trapped air masses simulated by the VOF model agree well with the experimental results. At the same time, the two simplified methods, such as “equal section ratio” and “equal diameter ratio”, are compared and analyzed in two-dimensional simulation. The comparison results show that the pressure result calculated by the “equal section ratio” method is closer to the experimental value.