| 摘要: |
| 透水框架因具有消能减速进而保护岸滩免受水流冲刷的功能，在河道治理、航道整治中得到广泛应用。最近提出了一种新型透水框架——扭双工字型透水框架，经动床试验表明具有显著的护滩效果，利用Vectrino三维流速仪在变坡水槽上精细测量了新型透水框架附近的水流结构。试验分析表明，扭双工字型透水框架抛投于床面后底层流速骤减（减速率达0.79~0.95）、表层流速增大、过渡层流速梯度加大，垂向流速不再服从对数分布；垂向最大紊动强度出现在框架群顶部附近，水流进入框架群后紊动强度逐渐加强，出框架群后达到极值，底表层紊动强度极值的位置发生偏离，表层位置较底层偏下游内侧；框架群内近底层水体能量大幅消减（消能率达0.93~0.99），下游水体能量恢复距离为38~56 m，利于滩面防护，而侧向边缘水体能量加强，易造成侧沿岸滩局部冲刷。研究成果对扭双工字型透水框架的设计、应用具有一定参考价值。 |
| 关键词: 扭双工字型透水框架 流速变化 紊动强度 单位水体能量 水槽试验 |
| DOI： |
| 分类号:U617.9 |
| 基金项目:国家自然科学基金资助项目（51309160）；交通运输部建设科技项目（2013328J17500） |
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| Experimental studies of erosion protection mechanism of twist double H permeable frame group |
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MA Ai-xing1, CAO Min-xiong2, TAN Lun-wu2, FU Zhong-min3, WANG Xiu-hong3, CAI Guo-zheng3
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1.State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute;2.State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering， Nanjing Hydraulic Research Institute， Research Center for Climate Change;3.Feilaixia Water Conservancy Management Bureau of Guangdong Province
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| Abstract: |
| The permeable frames have been widely applied to river and channel regulation since they serve the function of decelerating flow velocity and thus protecting bank and beaches against water erosion. Recently， a new-type permeable frame, twist double H permeable frame, is proposed， and movable-bed tests show that it has significant effects on bank and beach protection. A three-dimensional velocity meter (Vectrino) is used to measure the flow structure precisely near the frames on the flume. The study reveals that when the new permeable frames are thrown on the bed， the velocity of near-bottom layer plummets (deceleration rate of 0.79 to 0.95)， the surface velocity increases， the gradient of transition layer velocity increases， and the vertical velocity no longer obeys the logarithmic distribution； the largest vertical turbulence intensity appears near the top of the frame group， turbulence intensity gradually strengthens after the water flows into the frame group， and reaches the peak when flow is flowing out of the frame group. The peak location of turbulence intensity of the surface lies in the inner side of the downstream when compared with that of bottom. Water body energy near the bottom in the frame group dissipates dramatically (dissipation rate can reach 0.93 to 0.99). Water body energy recover distance in the downstream ranges from 38 m to 56 m， which is beneficial to beach protection， while the flow will cause local scour along the sides of the frame group due to the intensification of water body energy. These findings have certain reference values for the design and application of the new permeable frame group. |
| Key words: twist double H permeable frame velocity variations turbulent intensity specific water body energy flume experiment |
