(School of Transportation, Southeast University, Nanjing 211189, China )
为探究处于内涝过程超载状态节点的水流结构及水头损失,基于室内管道节点模型进行了87组不同边界条件的三维构造模型模拟,完成了室内试验与数值模拟的对比验证；采用定性定量分析、数据相关性拟合和 π 理论研究了孔径比(节点直径Φ m 和管道直径Φ p 的比值)、管道坡度、承压水头对节点内水流结构和水头损失的影响。研究结果表明:节点出口处的水量交互是产生水头损失的主要原因；局部水头损失系数K随孔径比的增大而增大,随超载水深、承压水头的增大而减小；通过 π 理论提出K=f(Re)的求解思路是可行的；两种孔径比节点的K值对坡度变化的响应不同,管道坡度的设计需要考虑节点孔径比的影响。研究成果补充了雨洪耦合模型中的节点水流结构,可为一维管网在节点处的水头损失计算提供经验数值和参考。
To explore the flow structure and head loss at surcharged nodes in the surcharging process, this paper simulated 87 cases with different boundary conditions using three-dimensional structural model based on the experimental pipeline node model. Comparison validation between the indoor experiment and the numerical simulation was completed. Qualitative and quantitative analysis, data correlation fitting and π theory were used to study the effect of diameter ratio (the ratio of node diameter Φ m to pipe diameter Φ p), pipe slope and confined pressure head on the flow structure and local head loss. The results show that the water flow interaction at the node-outlet is the main cause of head loss. The local head loss coefficient K is positively correlated with the diameter ratio, but negatively correlated with surcharging depth and confined pressure head. It is feasible to propose K=f(Re) relation formula by π theory. In addition, the value of K with two diameter ratios has different responses to the pipeline slope change, therefore, the effect of diameter ratio should be considered in the design of pipeline slope. The research results supplement the flow structure in the storm flood model, and can provide empirical values and law reference for the calculation of head loss of one-dimensional pipe network at the nodes.
耿艳芬,朱保航,钟颖萌.内涝过程中超载节点水流结构及水头损失分析[J].河海大学学报(自然科学版),2023,51(1):52-60.(GENG Yanfen, ZHU Baohang, ZHONG Yingmeng. Analysis of flow structure and head loss at surcharged nodes in surcharging process[J]. Journal of Hohai University (Natural Sciences),2023,51(1):52-60.(in Chinese))复制