生物附着现象对有压输水工程过流能力的影响

针对我国输水工程中生物污损现象造成的壁面混凝土剥落、有效过水断面缩小以及水质恶化等问题,依托南水北调中线某输水建筑物,开展了不同面积占比下的室内模型试验,并采用多孔介质域数值仿真分析了以淡水壳菜为主的生物附着下的有压管道三维流场和淡水壳菜附着对有压输水工程过流能力的影响。结果表明:受淡水壳菜附着的影响,有压管道水流呈主流偏移现象,近壁面水流质点动量交换更加剧烈；断面糙率与附着厚度及面积占比均呈正相关关系,低密度时,影响因素主要为淡水壳菜附着数目,高密度时,附着厚度为主要因素。

Effect of fouling organism attachment on flow capacity of pressurized water diversion system

Aiming at the adverse effects of wall concrete spalling, effective cross section reduction and water quality deterioration due to the phenomenon of biological fouling occurring frequently in Chinese water diversion projects, based on water diversion project in the middle route of the South-to-North Water Diversion Project, laboratory model experiments were carried out under different area ratios, and porous media domain was used to simulate the three-dimensional flow field of a pressurized pipeline under biological attachment dominated by limnoperna fortune.The influence of limnoperna fortunei attachment on the flow capacity of the pressurized pipeline was analyzed.The results show that the flow in the pressurized pipe presents the main flow deviation, and the particle momentum exchange near the wall is more intense.Section roughness was positively correlated with the attachment thickness and the area ratio.At low density, the main influencing factor was the attachment number of limnoperna fortunei.At high density, adhesion thickness is the main factor.