不同水力坡度对丁坝近区水流的影响
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摘要
采用超声水位和PIV流速测量技术,对不同水力坡度下非淹没丁坝近区的水流结构进行了试验研究。结果表明,随着水力坡度的降低,在坝头处,紊动强度较大的区域逐渐向主流区及上游扩散;在坝后,跌水最低点逐渐下移,漩涡中心向丁坝侧边壁靠近。回流区长度与宽度的变化和水力坡度的变化无明显对应关系,但坝头近壁区的流速与坝后回流区的长度及宽度存在高度响应的线性关系。研究成果揭示了丁坝在不同水力坡度下调整水流结构的机理,同时对各家测量得到的回流区长度不等有了较明确的答案,为工程中丁坝的设计及河道岸线的规划提供了科学依据。
This study investigated the flow structures in the near-field of an emerged spur dike under different hydraulic gradients by laboratory experiments using ultrasonic wave and PIV technical methods for measuring the water level and velocity, respectively. Experimental results showed that with the decrease in the hydraulic gradient,at the head of the dike, the area of the strong turbulence intensity gradually spread toward the main stream and upstream. At the downstream of the dike, the lowest point of the hydraulic gradient dropped gradually downward, and the vortex center was close to the wall of the dike side. There was no obvious relationship between the change in the length and width of the recirculation zone and the change in the hydraulic gradient; however, a highly linear relationship was observed between the velocity in the region near the dike head and the length and width of the recirculation zone. These research achievements reveal the mechanism of the regulative action of the dike to the flow structure under different hydraulic gradients. At the same time, these findings could clearly explain the difference in the length of the recirculation zone obtained by measurements of previous researchers and further provide a scientific basis for designing the spur dike and planning the river shoreline.
This study investigated the flow structures in the near-field of an emerged spur dike under different hydraulic gradients by laboratory experiments using ultrasonic wave and PIV technical methods for measuring the water level and velocity, respectively. Experimental results showed that with the decrease in the hydraulic gradient,at the head of the dike, the area of the strong turbulence intensity gradually spread toward the main stream and upstream. At the downstream of the dike, the lowest point of the hydraulic gradient dropped gradually downward, and the vortex center was close to the wall of the dike side. There was no obvious relationship between the change in the length and width of the recirculation zone and the change in the hydraulic gradient; however, a highly linear relationship was observed between the velocity in the region near the dike head and the length and width of the recirculation zone. These research achievements reveal the mechanism of the regulative action of the dike to the flow structure under different hydraulic gradients. At the same time, these findings could clearly explain the difference in the length of the recirculation zone obtained by measurements of previous researchers and further provide a scientific basis for designing the spur dike and planning the river shoreline.
引文
[1]Grade R J, Subramanya K, Nambudripad K D. Study of scour around spur-dikes[J]. Journal of the Hydraulics Division, 1961, 86(6):23-37.
[2]Rajaratnam N, Nwachukwu B A. Erosion near groynelike structures[J]. Journal of Hydraulic Research, 1983,21(4):277-287.
[3]Francis J R D, Pattanaik A B, Wearne S H. Observation of flow patterns around some simplified groyne structure in channels[C]//the Institution of Civil Engineers.Proceedings of the Institution of Civil Engineers. London:the Institution of Civil Engineers, 1968:829-846.
[4]胡华锋.丁坝绕流结构的试验及数值研究[D].长沙:长沙理工大学, 2006.Hu Huafeng. Experiment and numerical research of flow structure around spur dike[D]. Changsha:Changsha University of Science&Technology, 2006.
[5]许光祥,程昌华,刘建新.丁坝对河道水位影响的实验研究[J].重庆交通学院学报, 1994, 13(4):48-53.Xu Guangxiang, Cheng Changhua, Liu Jianxin. Influence on Water-Surface-Profile at the reach of river with spur-dike[J]. Journal of Chongqing Jiaotong University,1994, 13(4):48-53.
[6]高桂景.丁坝附近水流动能分布研究[J].水运工程,2007(11):75-79, 119.Gao Guijing. Distribution of pulsation kinetic energy of flow around spur dike[J]. Port&Waterway Engineering,2007(11):75-79, 119.
[7]陈稚聪,黑鹏飞,丁翔.丁坝回流分区机理及回流尺度流量试验研究[J].水科学进展, 2008, 19(5):613-617.Chen Zhicong, Hei Pengfei, Ding Xiang. Division and flow scale investigation of circulation zone around spur dike[J]. Advances in Water Science, 2008, 19(5):613-617.
[8]Tingsanchali T, Maheswaran S. 2-D Depth-average flow computation near groyne[J]. Journal of Hydraulic Engineering, 1990, 116(1):71-86.
[9]Mayerle R, Toro F M, Wang S S Y. Verification of a three-dimensional numerical model simulation of the flow in the vicinity of spur dikes[J]. Journal of Hydraulic Research, 1995, 33(2):178-196.
[10]Ouillon S, Dartus D. Three-dimensional computation of flow around groyne[J]. Journal of Hydraulic Engineering,1997, 123(11):962-970.
[11]李中伟,余明辉,段文忠,等.丁坝附近局部流场的数值模拟[J].武汉水利电力大学学报, 2000, 33(3):18-22.Li Zhongwei, Yu Minghui, Duan Wenzhong, et al. Numerical simulation of local flow field around spur dike[J]. Journal of Wuhan University of Hydraulic and Electric Engineering, 2000, 33(3):18-22.
[12]周宜林,道上正规,桧谷治.非淹没丁坝附近三维水流运动特性的研究[J].水利学报, 2004, 8:46-53.Zhou Yilin, Michiue M, Hinokidani O. Study on flow characteristics around the non-submerged spur-dikes[J].Journal of Hydraulic Engineering, 2004, 8:46-53.
[13]蔡亚希,魏文礼,刘玉玲.进口流速对丁坝回流长度影响的数值模拟研究[J].水资源与水工程学报, 2013,24(6):51-54, 59.Cai Yaxi, Wei Wenli, Liu Yuling. Study of numerical simulation on influence of inlet velocity on recirculation scale[J]. Journal of Water Resource&Water Engineering, 2013, 24(6):51-54, 59.
[14]雷亚,刘杰.基于Fluent的丁坝回流区数值模拟[J].水利科技与经济, 2015, 21(2):4-6.Lei Ya, Liu Jie. Simulation of the backflow zone around spur dike based on FLUENT[J]. Water Conservancy Science and Technology and Economy, 2015, 21(2):4-6.
[15]李子龙,寇军,张景新.明渠条件下单丁坝绕流特征的数值模拟[J].计算力学学报, 2016, 33(2):245-251.Li Zilong, Kou Jun, Zhang Jingxin. Numerical simulations of flow around a single spur dike in an open channel[J]. Chinese Journal of Computational Mechanics,2016, 33(2):245-251.
[2]Rajaratnam N, Nwachukwu B A. Erosion near groynelike structures[J]. Journal of Hydraulic Research, 1983,21(4):277-287.
[3]Francis J R D, Pattanaik A B, Wearne S H. Observation of flow patterns around some simplified groyne structure in channels[C]//the Institution of Civil Engineers.Proceedings of the Institution of Civil Engineers. London:the Institution of Civil Engineers, 1968:829-846.
[4]胡华锋.丁坝绕流结构的试验及数值研究[D].长沙:长沙理工大学, 2006.Hu Huafeng. Experiment and numerical research of flow structure around spur dike[D]. Changsha:Changsha University of Science&Technology, 2006.
[5]许光祥,程昌华,刘建新.丁坝对河道水位影响的实验研究[J].重庆交通学院学报, 1994, 13(4):48-53.Xu Guangxiang, Cheng Changhua, Liu Jianxin. Influence on Water-Surface-Profile at the reach of river with spur-dike[J]. Journal of Chongqing Jiaotong University,1994, 13(4):48-53.
[6]高桂景.丁坝附近水流动能分布研究[J].水运工程,2007(11):75-79, 119.Gao Guijing. Distribution of pulsation kinetic energy of flow around spur dike[J]. Port&Waterway Engineering,2007(11):75-79, 119.
[7]陈稚聪,黑鹏飞,丁翔.丁坝回流分区机理及回流尺度流量试验研究[J].水科学进展, 2008, 19(5):613-617.Chen Zhicong, Hei Pengfei, Ding Xiang. Division and flow scale investigation of circulation zone around spur dike[J]. Advances in Water Science, 2008, 19(5):613-617.
[8]Tingsanchali T, Maheswaran S. 2-D Depth-average flow computation near groyne[J]. Journal of Hydraulic Engineering, 1990, 116(1):71-86.
[9]Mayerle R, Toro F M, Wang S S Y. Verification of a three-dimensional numerical model simulation of the flow in the vicinity of spur dikes[J]. Journal of Hydraulic Research, 1995, 33(2):178-196.
[10]Ouillon S, Dartus D. Three-dimensional computation of flow around groyne[J]. Journal of Hydraulic Engineering,1997, 123(11):962-970.
[11]李中伟,余明辉,段文忠,等.丁坝附近局部流场的数值模拟[J].武汉水利电力大学学报, 2000, 33(3):18-22.Li Zhongwei, Yu Minghui, Duan Wenzhong, et al. Numerical simulation of local flow field around spur dike[J]. Journal of Wuhan University of Hydraulic and Electric Engineering, 2000, 33(3):18-22.
[12]周宜林,道上正规,桧谷治.非淹没丁坝附近三维水流运动特性的研究[J].水利学报, 2004, 8:46-53.Zhou Yilin, Michiue M, Hinokidani O. Study on flow characteristics around the non-submerged spur-dikes[J].Journal of Hydraulic Engineering, 2004, 8:46-53.
[13]蔡亚希,魏文礼,刘玉玲.进口流速对丁坝回流长度影响的数值模拟研究[J].水资源与水工程学报, 2013,24(6):51-54, 59.Cai Yaxi, Wei Wenli, Liu Yuling. Study of numerical simulation on influence of inlet velocity on recirculation scale[J]. Journal of Water Resource&Water Engineering, 2013, 24(6):51-54, 59.
[14]雷亚,刘杰.基于Fluent的丁坝回流区数值模拟[J].水利科技与经济, 2015, 21(2):4-6.Lei Ya, Liu Jie. Simulation of the backflow zone around spur dike based on FLUENT[J]. Water Conservancy Science and Technology and Economy, 2015, 21(2):4-6.
[15]李子龙,寇军,张景新.明渠条件下单丁坝绕流特征的数值模拟[J].计算力学学报, 2016, 33(2):245-251.Li Zilong, Kou Jun, Zhang Jingxin. Numerical simulations of flow around a single spur dike in an open channel[J]. Chinese Journal of Computational Mechanics,2016, 33(2):245-251.
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