丁坝群附近流场及局部冲刷的三维数值模拟
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摘要
为探索丁坝群附近水流流场,揭示其局部冲刷的形成机理,该文采用Flow-3d软件,选取RNG k-ε湍流模型和以希尔兹(Shields)数为基础的泥沙推移质输沙率模型对上挑丁坝群的周围流场分布和局部冲刷进行了三维数值模拟。研究发现,丁坝群间涡系结构复杂,第一座丁坝坝头处有一对反向的旋涡和下潜水流,切应力达到最大值,使得该位置有较大冲刷坑发生,解释了冲刷机理。冲刷坑的模拟深度和范围与实验结果吻合较好,表明该模型可以用于丁坝群及相关河道整治工程的流场和冲刷坑计算。
To reveal the mechanism of flow field and local scour around spur dikes, the present paper uses FLOW-3D software to simulate the three-dimensional flow and local scour around upward slopping spur dikes. Selected turbulence model is RNG k- ε model and the bed-load transport model is based on Shields number. Numerical simulation results show that the vortex is so complex between dikes. The bigger scour hole occurs in the first head of dike due to the combined effect of reverse vortexes, submerged flow and maximum shear stress. It also explains the scour mechanism. Obtained depth and scope of scour pit around spur dikes coincide well with experiment. It shows that the model can be applied to the calculation of flow field and scour pit around spur dikes and related river regulation engineering.
To reveal the mechanism of flow field and local scour around spur dikes, the present paper uses FLOW-3D software to simulate the three-dimensional flow and local scour around upward slopping spur dikes. Selected turbulence model is RNG k- ε model and the bed-load transport model is based on Shields number. Numerical simulation results show that the vortex is so complex between dikes. The bigger scour hole occurs in the first head of dike due to the combined effect of reverse vortexes, submerged flow and maximum shear stress. It also explains the scour mechanism. Obtained depth and scope of scour pit around spur dikes coincide well with experiment. It shows that the model can be applied to the calculation of flow field and scour pit around spur dikes and related river regulation engineering.
引文
[1]曹艳敏,张华庆,蒋昌波,等.丁坝冲刷坑及下游回流区流场和紊动特性试验研究[J].水动力学研究与进展,A辑,2008,23(5):560-570.CAO Yan-min,ZHANG Hua-qing,JIANG Chang-bo,et al.The experimental research of the flow field and turbulence characteristics in the scour and backflow region around a groin[J].Chinese Journal of Hydrodynamics,2008,23(5):560-570.
[2]张明进,白玉川,张华庆,等.基于非静压三维数值模型的丁坝水毁研究[J].水力发电学报,2014,33(3):179-188.ZHANG Ming-jin,BAI Yu-chuan,ZHANG Hua-qing,et al.Simulation of spurdike water destruction with 3D non-hydrostatic numerical model[J].Journal of Hydroelectric Engineering,2014,33(3):179-188.
[3]魏文礼,洪云飞,邵世鹏,等.梯形断面明渠丁坝绕流水力特性三维数值模拟[J].应用力学学报,2015,32(2):294-299.WEI Wen-li,HONG Yun-fei,SHAO Shi-peng,et al.3-dimensional numerical simulation of hydraulic characteristics of spur dike flow in a trapezoid open channel[J].Chinese Journal of applied mechanics,2015,32(2):294-299.
[4]李冰冻,李嘉,李克锋.丁坝水流的水槽试验及数值模拟研究[J].水动力学研究与进展,A辑,2013,28(2):176-183.LI Bing-dong,LI Jia,LI Ke-feng.Flume experiment and numerical simulation on flow around a spur dike[J].Chinese Journal of Hydrodynamics,2013,28(2):176-183.
[5]常福田,丰纬.丁坝群间合理间距的试验研究[J].河海大学学报,1992,20(4):7-14.CHANG Fu-tian,FENG Wei.Experiment at investigation of reasonable spacing among spur dikes[J].Journal of Hohai University,1992,20(4):7-14.
[6]HALTIGIN T W,BIRON P M,LAPOINTE M F.Predicting equilibrium scour-hole geometry near angled stream deflectors using a three-dimensional numerical flow model[J].Journal of Hydraulic Engineering-asce,2007,133(8):983-988.
[7]陆晶,倪丁凡,刘亚威,等.挑角对淹没丁坝附近河床变形影响的试验[J].武汉大学学报:工学版,2015,48(1):11-14.LU Jing,NI Ding-fan,LIU Ya-wei,et al.Experimental study of effects of spur-dike angle on local river bed deformation near a submerged spur-dike[J].Engineering Journal of Wuhan University,2015,48(1):11-14.
[8]刘玉玲,周孝德,杨国丽.基于WENO格式的天然河道丁坝群二维水流数值模拟[J].水动力学研究与进展,A辑,2010,25(1):93-98.LIU Yu-ling,ZHOU Xiao-de,YANG Guo-li.Numerical simulation of 2D depth-averaged model for rivers with groins based on WENO schemes[J].Chinese Journal of Hydrodynamics,2010,25(1):93-98.
[9]杨石磊,张耀哲.非淹没式丁坝群局部冲刷规律试验研究[J].水利水电技术,2013,44(11):81-84.YANG Shi-lei,ZHANG Yao-zhe.Study on law of local sour of non-submerged spur-dike group[J].Water Resources and Hydropower Engineering,2013,44(11):81-84.
[10]许慧,李国斌,尚倩倩,等.淹没丁坝群二维水流数值模拟新方法[J].水科学进展,2014,25(3):407-413.XU Hui,LI Guo-bin,SHANG Qian-qian,et al.A new numerical simulation approach for 2-D flow with submerged spur-dikes[J].Advances in Water Science,2014,25(3):407-413.
[11]张瑞瑾.河流泥沙动力学[M].北京,中国:水利水电出版社,1998.ZHNG Rui-Jin.River sediment dynamics[M].Beijing,China:China Water Power Press,1988.
[12]周哲宇,陶东良,哈岸英,等.丁坝局部冲刷研究现状与展望[J].人民黄河,2010,32(6):18-21.ZHOU Zhe-yu,TAO Dong-liang,HA An-ying,et al.The research status and prospect of local scour around spur-dike[J].Yellow River,2010,32(6):18-21.
[13]YAKHOT,ORSZAG S A.Renormalization-group analysis of turbulence[J].Journal of Scientific Computing,1986,1(1):3-51.
[14]CHEN Bing.The numerical simulation of local scour in front of a vertical-wall breakwater[C].Proceedings of the Conference of Global Chinese Scholars on Hydrodynamics,Shanghai,China,2006.
[15]ENGELUND F,FREDSOE J.A sediment transport model for straight alluvial channels[J].Nordic Hydrology,1976,7(5):293-306.
[16]JENNIFER Duan.Experiment study and numerical simulation of flow and sediment transport around a series spur dikes[D].The University of Arizona,Arizona,2011.
[2]张明进,白玉川,张华庆,等.基于非静压三维数值模型的丁坝水毁研究[J].水力发电学报,2014,33(3):179-188.ZHANG Ming-jin,BAI Yu-chuan,ZHANG Hua-qing,et al.Simulation of spurdike water destruction with 3D non-hydrostatic numerical model[J].Journal of Hydroelectric Engineering,2014,33(3):179-188.
[3]魏文礼,洪云飞,邵世鹏,等.梯形断面明渠丁坝绕流水力特性三维数值模拟[J].应用力学学报,2015,32(2):294-299.WEI Wen-li,HONG Yun-fei,SHAO Shi-peng,et al.3-dimensional numerical simulation of hydraulic characteristics of spur dike flow in a trapezoid open channel[J].Chinese Journal of applied mechanics,2015,32(2):294-299.
[4]李冰冻,李嘉,李克锋.丁坝水流的水槽试验及数值模拟研究[J].水动力学研究与进展,A辑,2013,28(2):176-183.LI Bing-dong,LI Jia,LI Ke-feng.Flume experiment and numerical simulation on flow around a spur dike[J].Chinese Journal of Hydrodynamics,2013,28(2):176-183.
[5]常福田,丰纬.丁坝群间合理间距的试验研究[J].河海大学学报,1992,20(4):7-14.CHANG Fu-tian,FENG Wei.Experiment at investigation of reasonable spacing among spur dikes[J].Journal of Hohai University,1992,20(4):7-14.
[6]HALTIGIN T W,BIRON P M,LAPOINTE M F.Predicting equilibrium scour-hole geometry near angled stream deflectors using a three-dimensional numerical flow model[J].Journal of Hydraulic Engineering-asce,2007,133(8):983-988.
[7]陆晶,倪丁凡,刘亚威,等.挑角对淹没丁坝附近河床变形影响的试验[J].武汉大学学报:工学版,2015,48(1):11-14.LU Jing,NI Ding-fan,LIU Ya-wei,et al.Experimental study of effects of spur-dike angle on local river bed deformation near a submerged spur-dike[J].Engineering Journal of Wuhan University,2015,48(1):11-14.
[8]刘玉玲,周孝德,杨国丽.基于WENO格式的天然河道丁坝群二维水流数值模拟[J].水动力学研究与进展,A辑,2010,25(1):93-98.LIU Yu-ling,ZHOU Xiao-de,YANG Guo-li.Numerical simulation of 2D depth-averaged model for rivers with groins based on WENO schemes[J].Chinese Journal of Hydrodynamics,2010,25(1):93-98.
[9]杨石磊,张耀哲.非淹没式丁坝群局部冲刷规律试验研究[J].水利水电技术,2013,44(11):81-84.YANG Shi-lei,ZHANG Yao-zhe.Study on law of local sour of non-submerged spur-dike group[J].Water Resources and Hydropower Engineering,2013,44(11):81-84.
[10]许慧,李国斌,尚倩倩,等.淹没丁坝群二维水流数值模拟新方法[J].水科学进展,2014,25(3):407-413.XU Hui,LI Guo-bin,SHANG Qian-qian,et al.A new numerical simulation approach for 2-D flow with submerged spur-dikes[J].Advances in Water Science,2014,25(3):407-413.
[11]张瑞瑾.河流泥沙动力学[M].北京,中国:水利水电出版社,1998.ZHNG Rui-Jin.River sediment dynamics[M].Beijing,China:China Water Power Press,1988.
[12]周哲宇,陶东良,哈岸英,等.丁坝局部冲刷研究现状与展望[J].人民黄河,2010,32(6):18-21.ZHOU Zhe-yu,TAO Dong-liang,HA An-ying,et al.The research status and prospect of local scour around spur-dike[J].Yellow River,2010,32(6):18-21.
[13]YAKHOT,ORSZAG S A.Renormalization-group analysis of turbulence[J].Journal of Scientific Computing,1986,1(1):3-51.
[14]CHEN Bing.The numerical simulation of local scour in front of a vertical-wall breakwater[C].Proceedings of the Conference of Global Chinese Scholars on Hydrodynamics,Shanghai,China,2006.
[15]ENGELUND F,FREDSOE J.A sediment transport model for straight alluvial channels[J].Nordic Hydrology,1976,7(5):293-306.
[16]JENNIFER Duan.Experiment study and numerical simulation of flow and sediment transport around a series spur dikes[D].The University of Arizona,Arizona,2011.