排水管道堵塞时的CFD数值模拟

排水管道堵塞会降低其输水能力,严重时会影响区域排水系统的正常运行。堵塞后排水管道形成压力流,会在地面形成冒溢,本文针对压力流排水管道堵塞问题,用FLUENT软件对管道堵塞进行CFD数值模拟,分析了堵塞管道流态及堵塞程度单因子变量对沿管道长度方向压力和流速的影响。在基准工况下,堵塞位置后上方0~3 m区域流速增加,堵塞位置后下方0~5 m范围内流速降低,且在该区域下方形成水舌,对压力突变存在沿管道流动方向堵塞位置之后5 m范围内,堵塞使其前方位置产生憋压,后方产生失压。瞬间堵塞后,对于堵点较远区域流态及压力并无产生明显影响。堵塞高度、堵塞长度、堵塞位置对管道水流压力的影响顺序为：堵塞高度>堵塞长度>堵塞位置。

CFD Numerical Simulation on Blockage of Drainage Pipeline in Utility Tunnel

Pipeline blockage will reduce water carrying capacity of drainage system, and have a serious affect on regional drainage system in severe cases. After the blockage, the drainage pipe will form a pressure flow, which will cause overflow on the ground. For pressure flow drainage pipes. The article used FLUENT software to simulate CFD numerical simulation of pipeline blockage, and analyzed the flow pattern of the blocked pipe and the influence of single factor variable of blockage degree on the pressure and flow velocity along the pipeline length. It concluded that in the benchmark working condition, the flow velocity increases in the region from 0 to 3m above the blockage position and decreases in the region from 0 to 5m below the blockage position, and a water tongue is formed below the region. The abrupt change of influence on pressure exists within 5m after the blockage position along the flow direction of the pipeline. The clogging causes a pressure in the front position of the blockage, and a pressure loss occurs in the rear. After the instantaneous blockage, there is no significant influence on the flow state and pressure in the far point.The order of the influence of the blockage height, blockage length and blockage position on the water flow pressure of the pipeline are as follows: the blockage height is the largest, the blockage length is second, and the blockage position is the smallest.