| 李琳,顾怀猛,谭义海.淤积体对排沙漏斗水沙分离性能的影响机理研究[J].水利学报,2025,56(2):227-239 |
| 淤积体对排沙漏斗水沙分离性能的影响机理研究 |
| Research on influence mechanism of sand accumulation on water-sediment separation performance of vortex-settling basins |
| 投稿时间：2024-08-06 |
| DOI：10.13243/j.cnki.slxb.20240506 |
| 中文关键词: 排沙漏斗 模型试验 淤积体 空气涡形态 流场特性 |
| 英文关键词: vortex-settling basins model experiments sedimentation body air core shape flow field characteristics |
| 基金项目:国家自然科学基金项目(52069028) |
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| 摘要点击次数: 600 |
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| 中文摘要: |
| 为揭示淤积体对排沙漏斗水沙分离性能的影响机理，开展不同厚度淤积体下的浑水模型试验，并利用声学多普勒流速仪量测三维流场，观测空气涡形态变化。研究结果表明：不同进流量下排沙耗水率均随淤积体厚度的增大而增大，泥沙截除率随淤积体厚度增加而逐渐降低，不同淤积厚度下排沙耗水率是无淤积体时的1.27～2.14倍，泥沙截除率降幅33%～57%;淤积体导致漏斗流场特性发生改变，泥沙淤积厚度增加使空气涡由无淤积时的稳定贯穿变化至频繁摆动并偏离排沙底孔，不同水沙条件下涡径减小5.95%~53.07%，使排沙耗水率增大;漏斗室内自由涡范围和强度随淤积体厚度增加而减小，设计流量下切向流速平均减小20%~55%，位于强迫涡和自由涡间的环形低流速带宽度与无淤积情况相比增大33%～40%，不利于水沙的螺旋流分离，横向环流强度减弱，不利于泥沙向底孔输移，致使淤积加剧，从而进一步削减旋流强度;径向及垂向紊动强度随泥沙淤积厚度增加分别增大10%~110%和12%~120%，致使悬移质泥沙难以沉降，截除率大幅降低。 |
| 英文摘要: |
| In order to reveal the influence mechanism of sediment accumulation on the water-sediment separation performance of the Vortex-settling basins (VSB),the muddy water model tests were conducted under sediment accumulation of different thicknesses.The three-dimensional flow field was measured by acoustic Doppler velocimeter,and the shape change of air core was observed.The research results indicate that under different inflow rates,the sediment discharge water consumption rate increases with the increase in the thickness of the sediment accumulation body,and the sediment interception rate gradually decreases as the thickness of the sediment accumulation increases.The sediment discharge water consumption rate under different sediment thicknesses is 1.27 to 2.14 times that without sediment accumulation,and the sediment interception rate decreases by 33% to 57%.The sediment accumulation body leads to changes in the flow field characteristics of the VSB.The increase in sediment accumulation thickness causes the air core to change from a stable penetration when there is no sediment accumulation to frequent oscillation and deviation from the flushing orifice.Under different water and sediment conditions,the air core diameter decreases by 5.95% to 53.07%,which increases the sediment discharge water consumption rate.The range and intensity of the free vortex in the VSB decrease as the thickness of the sediment accumulation body increases,and the average tangential velocity under the design flow decreases by 20% to 55%.The width of the annular low-velocity zone between the forced vortex and the free vortex increases by 33% to 40% compared to the situation without sediment accumulation,which is not conducive to the spiral flow separation of water and sediment.The intensity of the transverse circulation weakens,which is not conducive to the transfer of sediment to the flushing orifice,leading to intensified sediment accumulation,thereby further reducing the swirl intensity.The radial and vertical turbulent intensities increase by 10% to 110% and 12% to 120% respectively with the increase in sediment accumulation thickness,making it difficult for suspended sediment to settle,and the interception rate is significantly reduced. |
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