闸门对水力过渡特性影响研究

Influence of Sluice Gate on the Hydraulic Transition of Water Channel

结合南水北调中线输水工程实际,采用显式的特征线法求解明渠和有压管道的圣维南方程。在长距离输水问题中,模拟段包含多个控制闸门。提出闸门处的水力过渡连接模型,在已有的两个特征方程的基础上补充闸孔出流公式和流量连续条件,分析闸门运行对渠道中水流的影响。利用窄缝法将明渠和暗管水流进行统一求解,采用变时步法克服扰动波在明渠和暗管中传播速度相差悬殊而导致的时间步长不协调问题。在明渠和暗管的连接处考虑水流的局部水头损失,更好地反应了非恒定流中扰动的传播特性。实际模拟输水渠道具有多个控制闸门和退水闸门的问题,分析了闸门对渠道中非恒定流的影响。

For studying the influences of sluice gates on the channel flow of the Middle Route of South-to-North Water Diversion Project, the Saint-Venant equations for unsteady open channel and pressure pipe flows are combined based on the narrow slot assumptions and solved by using the explicit characteristic line method. A hydraulic connection model for sluice gate is proposed and the discharge rate formulation and the continuity condition are applied besides the two compatibility equations. For the joint solution of open channel and pressure pipe flow equations, the time step variation technique is used, by which the large time step difference arose from the wave speed difference between the open channel and pressure pipe flows are overcome. The local energy loss at the connection section of the open channel and the pipe are considered in the calculation in order to properly reflect the propagation characteristics of disturb wave in unsteady flow. The model calculation shows the analysis on hydraulic transition is feasible.