| 摘要: |
| 【目的】研究渠系节点区域悬移质淤积对支渠引水分流的影响。【方法】基于中下级渠道中直角分水口区域建立水流计算模型，借助FLUENT求解节点区域水力要素，采用水沙非耦合方法，通过MATLAB编译程序求解悬移质泥沙连续方程和河床变形方程。【结果】若以初始引水流量的90%作为分水支渠供水保证率，在上游给定的来水来沙条件下，最大清淤周期为7.5 a。在淤积末期，分水口区域泥沙淤积形成拦门沙坎，影响主支渠分流流速比η，过流能力减小为初始过流量的65.6%，近床面处过流宽度仅为支渠宽的37.5%。【结论】渠系节点淤积对支渠过水能力影响较大。 |
| 关键词: 渠系；节点； 悬移质； 淤积分布； 过流能力 |
| DOI：10.13522/j.cnki.ggps.2017.0229 |
| 分类号: |
| 基金项目: |
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| Numerical Simulation of Distribution of Sediment Deposition on the Joints in Canal Systems |
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WANG Yanzhao, ZHANG Yaozhe
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College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, China
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| Abstract: |
| 【Objective】 Understanding how suspended sediments deposit in a canal system is critical to ensure canal service and in this paper, we numerically simulated sediment deposition at joints and diversion in a canal system. 【Method】 We developed a flow model for the rectangular outlet region in a lateral channel and solved water flow through it using the software FLUENT. The sediment transport and deposition, as well as the change in channel bed due to sediment deposition were solved by decoupling the fluid model and the sediment transport model; the associated equations were solved numerically using MATLAB. 【Result】 The results showed that, when upstream conditions remained the same, the maximum dredging cycle is 7.5 years if we took 90% of the design flowing capacity of the canal as minimum capacity that the channel should have after flow-capacity reduction due to sediment deposition. Sediment deposition created a sand barrier at the diversion area, impacting the flow rate ratio between the mainstream and its tributary. This consequently reduced the flow rate to 65.6% of its design value, and the width of the water flow cross-section at the canal bed was reduced to 37.5% of the width of the branch canal. 【Conclusion】 Sediment deposition at irrigation channel joints and diversion has considerable impact on flowing capacity of the main channel and its branches, and the proposed model help improve their management. |
| Key words: irrigation system; node; suspended load; sedimentation distribution; flow capacity |
