悬板开孔对排沙漏斗流场特性的影响

排沙漏斗的水沙分离性能取决于其流场特性，为了弄清楚悬板开孔对流场特性的影响，利用粒子图像测速技术和数值模拟方法，分别对悬板溢流段和非溢流段同时均匀布孔、仅在非溢流段布孔和无孔时的排沙漏斗流场特性开展研究。结果表明:①布孔位置不影响涡流性质但影响其强度，均匀布孔时涡流强度最小，不利于水沙离心分离；②无孔和仅在非溢流段布孔时的流场特性有利于泥沙径向输移、沉降和排出，均匀布孔径向速度和二次流流速减小不利于泥沙输移和排出；③仅在悬板非溢流段布孔时悬板表面速度大于其他方案，泥沙不易淤积于悬板。为减少悬板上的泥沙淤积量且同时要保证较高的泥沙截除率时可采用仅在悬板非溢流段布孔的方案优化悬板体型。

Effects of the opening of the deflector on the flow characteristics in the vortex settling basin

The water and sediment separation performance of the Vortex Settling Basin (VSB) depends on the characteristics of the velocity field. To understand the influence of the opening of the deflector on the flow field, VSBs with the deflector partially perforated on the non-overflow area entirely perforated and without any openings were tested with Particle Image Velocimetry (PIV) and simulated with a large eddy turbulence model. The results showed that:① The opening positions did not affect the vortex properties of the VSBs but did affect their strength. The swirl intensity of the entirely perforated VSB was the smallest, which made it difficult to extract sediment by centrifugal force. ② The VSBs without any openings were partially perorated helped the sediment to be transported along the radial direction, move down and be discharged, but the radial velocity and secondary flow in the entirely perforated VSB were reduced, which caused the sediment to be deposited on the floor. ③ The velocity on the partially perforated deflector was the greatest, which could prevent the sediment from depositing on the deflector. Therefore, to reduce the amount of particles deposited on the deflector of the VSB and to ensure a high sediment trapping efficiency, it is better to choose a deflector that is partially perforated on the non-overflow area.