弯道流水域热浮力排放扩散器参数优化物理模型试验研究

弯道河流水域排放口布置常选择在弯道凹岸侧,以充分利用弯道环流加快稀释,然而弯道环流条件下排放口近区稀释特性与均匀流条件下存在较大差异,相关研究较少。本文在大比例尺物理模型试验中模拟复杂地形和弯道流动条件下扩散器热浮力排放近区稀释规律,采用平面激光诱导荧光(Planar Laser Induced Fluorescence,PLIF)技术进行断面浓度测量,分析了弯道环流对近区浮射流稀释扩散的影响,对扩散器出流仰角、出流水平方位角和离岸距离等进行了优化,在此基础上提出了适用于弯道水域地形条件热浮力排放的近水平非等高多喷口离岸向排放型式。研究结果对于类似弯道水域热浮力排放扩散器优化研究具有参考意义。

Physical model study on diffuser parameter optimization for thermal buoyant discharge into bend flow

The outfall of waste discharge into bend flow area is usually located at the cut bank to take full advantage of the spiral flow for fast mixing. While the near field mixing characteristic in bend flow is different from that in straight channel and the related research is rare. In this paper,the near field mixing process of a thermal buoyant discharge by a diffuser into bend flow is simulated using a large scaled physi-cal model. The Planar Laser Induced Fluorescence (PLIF) technology is used to measure the concentration at certain sections. The impact of bend secondary flow on the buoyant jet mixing is analyzed. Then the dis-charge vertical angle, horizontal direction angle and distance from bank are optimized. At last the diffuser discharge nearly horizontal offshore at different height level is proposed as the most suitable pattern for the thermal buoyant discharge into the bend flow. The research result has reference meaning for diffuser optimi-zation study of similar thermal buoyant discharge into bend river area.