设置保水堰管涵输水系统的水力瞬变数值仿真

为研究大型调水工程的水力瞬变过程，采用明渠非恒定流方程及Preissiman方法模拟无压管涵非恒定流、有压管涵水击和明满交替流，提出了设置保水堰的长距离管涵输水系统的水力学仿真模型。所建立的数值模型可模拟包括管涵明满交替和保水堰跌水等复杂的水流现象。数值仿真结果表明，在检修闸门和下游管涵之间设置保水堰，可以调节输水管道内的压力，避免紧急启闭时发生液柱分离以及检修闸门突然关闭时因明满流交替而产生强烈的冲击水压。

Numerical simulation of hydraulic transients in conduit networks for water transfer with retaining weirs

Based on the fundamental equation for unsteady flow in open channel the Preissman method is applied to establish the model for simulating the hydraulic transient in long distance conduit water transfer system with retaining weirs. The flow regimes to be simulated include non_pressure unsteady flow, water hammer of pressurized conduit and transition process of open channel flow to pressure flow, with submerged and free overflow regime of the retaining weir are to be considered. The result shows that the retaining weirs not only play the role of regulating the pressure of conduit but also prevent from the occurrence of water column separation phenomenon during emergent stopping of water supply and strong impact force acting on emergency gates due to the alternative transition between open channel flow and pressure flow.