| 摘要: |
| 【目的】得到含刚性沉水植物明渠的水流结构。【方法】采用粒子图像测速仪（PIV），用有机玻璃棒模拟刚性植物，在不同来水流量、植物密度条件下对明渠水流结构进行了试验研究。【结果】无植物时平均流速沿垂向呈对数分布规律，有植物时则呈现明显的分区分布特性。无植物时紊动强度值沿垂向变化不大，有植物时在植物顶端位置处紊动最剧烈。流量或植物密度越大，植物顶端位置的流速梯度就越大，植物层上方的流速最大值也越大。植物密度越大，植物顶端位置的紊动强度越大，植物密度对水流紊动强度由最大值减小到最小值的区域影响很大。【结论】刚性沉水植物的存在会改变水流结构，增强紊动掺混，增强流体质点交换和能量传递，且上述影响会随着流量或植物密度的增大而增强。 |
| 关键词: 刚性沉水植物；明渠流动；水流结构；试验研究 |
| DOI：10.13522/j.cnki.ggps.2019040 |
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| Experimental study on flow structure of open channels with rigid submerged plants |
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WANG Zijian, DING Xue, JI Qingfeng
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College of Hydraulic Science and Engineering, Yangzhou University, Yangzhou 225009, China
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| Abstract: |
| 【Objective】This study is to explore the flow structure of open channel with rigid submerged plants.【Method】The flow structure of open channel was studied under different inflow and plant density conditions using particle image velocimeter (PIV) and plexiglass rod to simulate rigid plants.【Result】It was found that the average velocity distribution along the vertical line was logarithmic in the absence of plants, while it showed obvious zonal distribution in the presence of plants. The intensity of turbulence did not change much in the direction of water depth when there was no plant, but the turbulence was most intense in the canopy when there were plants. The greater the flow rate or plant density, the greater the velocity gradient at the canopy and the maximum velocity above the plant layer were. The greater the plant density, the greater the turbulence intensity were in the canopy. The plant density had a great influence on the region where the turbulence intensity decreased from the maximum to the minimum.【Conclusion】The existence of rigid submerged plants will change the flow structure, enhance turbulent mixing, enhance fluid particle exchange and energy transfer, and these effects will increase with the flow or plant density. |
| Key words: rigid submerged plant; open channel flow; flow structure; experimental study |
