汇流比对U形弯曲交汇河道中污染物离散系数的影响
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摘要
针对弯曲河道交汇区污染物离散系数的分布特征进行研究,通过建立U形弯曲交汇河道水气两相流数学模型,进行交汇区水动力数值模拟。数学模型经试验数据验证后,模拟分析了不同汇流比对弯道交汇区水流结构和离散特性的影响,离散系数采用二维离散张量法进行计算。结果表明,支流入汇导致交汇断面附近纵向和横向离散系数达到峰值,该峰值随着汇流比的增大而增大;横向离散系数沿程分布呈现单峰结构,纵向离散系数沿程分布呈现双峰结构。
The distribution characteristics of pollutant dispersion coefficient in the confluence of a curved river with tributary are studied. The mathematical model of air-water two-phase flow in the U-shaped confluent channel is established and verified by the data of previous laboratory experiments. Based on the simulation results,the influence of different discharge ratio on the flow structure and dispersion characteristics of confluent curved river is analyzed,in which the dispersion coefficient is calculated by the two-dimensional tensor method. The results show that the dispersion coefficient reaches the peak value in the vicinity of convergence,and the peak value increases with the increase of discharge ratio. Moreover, the longitudinal dispersion coefficient shows a single peak distribution along the river,while the transversal dispersion coefficient presents a double-peak structure.
The distribution characteristics of pollutant dispersion coefficient in the confluence of a curved river with tributary are studied. The mathematical model of air-water two-phase flow in the U-shaped confluent channel is established and verified by the data of previous laboratory experiments. Based on the simulation results,the influence of different discharge ratio on the flow structure and dispersion characteristics of confluent curved river is analyzed,in which the dispersion coefficient is calculated by the two-dimensional tensor method. The results show that the dispersion coefficient reaches the peak value in the vicinity of convergence,and the peak value increases with the increase of discharge ratio. Moreover, the longitudinal dispersion coefficient shows a single peak distribution along the river,while the transversal dispersion coefficient presents a double-peak structure.
引文
[1]ELDER,J W.The dispersion of marked fluid in turbulent shear flow[J].Journal of Fluid Mechanics,1959,5(4):544-560.
[2]FISCHER H B,LIST E J,KOH R C Y,et al.Mixing in inland and coastal waters[M].London:Academic Press,1979.
[3]STEFAN H,GULLIVER J S.Effluent mixing zone in a shallow river[J].Journal of the Environmental Engineering Division,1978,104(2):199-213.
[4]蒋忠锦,王继徽.天然河流和湖泊岸流污染带横向混合系数计算[J].湖南大学学报(自然科学版),1997,24(1):29-32.(JIANG Zhongjin,WANG Jihui.Calculation of transverse mixed coefficient in the polluted zone of natural river s and lakes bank flow[J].Journal of Hunan University(Natural Sciences),1997,24(1):29-32.(in Chinese))
[5]郑旭荣,邓志强,申继红.顺直河流横向紊动扩散系数[J].水科学进展,2002,13(6):670-674.(ZHENG Xurong,DENG Zhiqiang,SHEN Jihong.Transverse turbulent dispersion coefficient in straight channel[J].Advances in Water Science,2002,13(6):670-674.(in Chinese))
[6]RUTHERFORD J.River mixing[M].New York:John Wiley and Sons,1994.
[7]BAEK K O,SEO I W,JEONG S J.Evaluation of dispersion coefficients in meandering channels from transient tracer tests[J].Journal of Hydraulic Engineering,2006,132(10):1021-1032.
[8]SEO I W,LEE M E,BAEK K O.2D modeling of heterogeneous dispersion in meandering channels[J].Journal of Hydraulic Engineering,2008,134(2):196-204.
[9]BOXALL J B,GUYMER I.Analysis and prediction of transverse mixing coefficients in natural channels[J].Journal of Hydraulic Engineering,2003,129(2):129-139.
[10]BAEK K O,SEO I W.Transverse dispersion caused by secondary flow in curved channels[J].Journal of Hydraulic Engineering,2011,137(10):1126-1134.
[11]李成光,槐文信,曾玉红,等.强弯河道水流结构及离散特性研究[J].华中科技大学学报(自然科学版),2014(2):64-67.(LI Chengguang,HUAN Wenxin,ZENG Yuhong,et al.Flow structures and dispersion characteristics in strongly curved open channels[J].Journal of Huazhong University(Natural Sciences),2014(2):64-67.(in Chinese))
[12]高伟,杨中华.弯道纵向离散系数研究进展[J].中国农村水利水电,2009(2):5-8.(GAO Wei,YANG Zhonghua.Advance in longitudinal dispersion coefficient of river bends[J].China Rural Water and Hydropower,2009(2):5-8.(in Chinese))
[13]LANCKAERT K,de VRIEND H J.Secondary flow in sharp open-channel bends[J].Journal of Fluid Mechanics,2004,498(1):353-380.
[14]ANDREA M,MATTIA Z.Effects of velocity gradients and secondary flow on the dispersion of solutes in a meandering hannel[J].Journal of Hydraulic Engineering,2006,132(12):295-302.
[15]孙远敬,徐建新.基于CFD的河流弯道二次流的三维数值模拟[J].应用力学学报,2015(3):502-507.(SUN Yuanjin,XU Jianxin.Three-dimensional numerical simulation of secondary flow in river bends based on CFD[J].Chinese Journal of Applied Mechanics,2015(3):502-507.(in Chinese))
[16]江帆,陈维平,陈敏,等.弯曲性分叉河道中污染物扩散性的初步研究[J].水资源保护,2006,22(4):30-32.(JIANG Fan,CHEN Weipin,CHEN Min,et al.Primary study on diffusion of contaminants in meandering furcated rivers[J].Water Resources Protection,2006,22(4):30-32.(in Chinese))
[17]CHEN Liping,CHENG Jingtao,DENG Guangfa.Anisotropic diffusion of volatile pollutants at air-water interface[J].Water Science and Engineering,2013,6(1):153-163.
[18]路川藤,黄华聪,钱明霞.长江口北槽丁坝坝田区潮流及污染物迁移扩散特征[J].河海大学学报(自然科学版),2016,44(3):265-271.(LU Chuanteng,HUANG Huacong,QIAN Mingxia.Tidal current and pollutant diffusion characteristucs in spur dike field of north passage in yangtze estuary[J].Journal Of Hohai University(Natural Sciences),2016,44(3):265-271.(in Chinese))
[19]冯丽华.明渠弯道三维水流数值模拟研究[D].扬州:扬州大学,2007.
[20]HIRT C W,NICHOLS B D.A computational method for free surface hydrodynamics[J].Journal of Pressure Vessel Technology,1981,103(2):136-141.
[21]高艳,黄社华,李琼.弯道干流与支流交汇口垂线流速分布的试验研究[J].水电能源科学,2012,30(7):90-93.(GAO Yan,HUANG Shehua,LI Qiong.Experimental research on velocity distribution along depth at junction of bend stream with branch afflux[J].Water Resources and Power,2012,30(7):90-93.(in Chinese))
[22]CIFANI P,MICHALEK W R,PRIEMS G J M,et al.A comparison between the surface compression method and an interface reconstruction method for the VOF approach[J].Computers&Fluids,2016,136:421-435.
[23]王福军.计算流体动力学分析[M].北京:清华大学出版社,2004.
[24]FISCHER H B.On the tensor form of the bulk dispersion coefficient in a bounded skewed shear flow[J].Journal of Geophysical Research:Oceans,1978,83(C5):2373-2375.
[25]ALAVIAN V.Dispersion tensor in rotating flows[J].Journal of Hydraulic Engineering,1986,112(8):771-777.
[2]FISCHER H B,LIST E J,KOH R C Y,et al.Mixing in inland and coastal waters[M].London:Academic Press,1979.
[3]STEFAN H,GULLIVER J S.Effluent mixing zone in a shallow river[J].Journal of the Environmental Engineering Division,1978,104(2):199-213.
[4]蒋忠锦,王继徽.天然河流和湖泊岸流污染带横向混合系数计算[J].湖南大学学报(自然科学版),1997,24(1):29-32.(JIANG Zhongjin,WANG Jihui.Calculation of transverse mixed coefficient in the polluted zone of natural river s and lakes bank flow[J].Journal of Hunan University(Natural Sciences),1997,24(1):29-32.(in Chinese))
[5]郑旭荣,邓志强,申继红.顺直河流横向紊动扩散系数[J].水科学进展,2002,13(6):670-674.(ZHENG Xurong,DENG Zhiqiang,SHEN Jihong.Transverse turbulent dispersion coefficient in straight channel[J].Advances in Water Science,2002,13(6):670-674.(in Chinese))
[6]RUTHERFORD J.River mixing[M].New York:John Wiley and Sons,1994.
[7]BAEK K O,SEO I W,JEONG S J.Evaluation of dispersion coefficients in meandering channels from transient tracer tests[J].Journal of Hydraulic Engineering,2006,132(10):1021-1032.
[8]SEO I W,LEE M E,BAEK K O.2D modeling of heterogeneous dispersion in meandering channels[J].Journal of Hydraulic Engineering,2008,134(2):196-204.
[9]BOXALL J B,GUYMER I.Analysis and prediction of transverse mixing coefficients in natural channels[J].Journal of Hydraulic Engineering,2003,129(2):129-139.
[10]BAEK K O,SEO I W.Transverse dispersion caused by secondary flow in curved channels[J].Journal of Hydraulic Engineering,2011,137(10):1126-1134.
[11]李成光,槐文信,曾玉红,等.强弯河道水流结构及离散特性研究[J].华中科技大学学报(自然科学版),2014(2):64-67.(LI Chengguang,HUAN Wenxin,ZENG Yuhong,et al.Flow structures and dispersion characteristics in strongly curved open channels[J].Journal of Huazhong University(Natural Sciences),2014(2):64-67.(in Chinese))
[12]高伟,杨中华.弯道纵向离散系数研究进展[J].中国农村水利水电,2009(2):5-8.(GAO Wei,YANG Zhonghua.Advance in longitudinal dispersion coefficient of river bends[J].China Rural Water and Hydropower,2009(2):5-8.(in Chinese))
[13]LANCKAERT K,de VRIEND H J.Secondary flow in sharp open-channel bends[J].Journal of Fluid Mechanics,2004,498(1):353-380.
[14]ANDREA M,MATTIA Z.Effects of velocity gradients and secondary flow on the dispersion of solutes in a meandering hannel[J].Journal of Hydraulic Engineering,2006,132(12):295-302.
[15]孙远敬,徐建新.基于CFD的河流弯道二次流的三维数值模拟[J].应用力学学报,2015(3):502-507.(SUN Yuanjin,XU Jianxin.Three-dimensional numerical simulation of secondary flow in river bends based on CFD[J].Chinese Journal of Applied Mechanics,2015(3):502-507.(in Chinese))
[16]江帆,陈维平,陈敏,等.弯曲性分叉河道中污染物扩散性的初步研究[J].水资源保护,2006,22(4):30-32.(JIANG Fan,CHEN Weipin,CHEN Min,et al.Primary study on diffusion of contaminants in meandering furcated rivers[J].Water Resources Protection,2006,22(4):30-32.(in Chinese))
[17]CHEN Liping,CHENG Jingtao,DENG Guangfa.Anisotropic diffusion of volatile pollutants at air-water interface[J].Water Science and Engineering,2013,6(1):153-163.
[18]路川藤,黄华聪,钱明霞.长江口北槽丁坝坝田区潮流及污染物迁移扩散特征[J].河海大学学报(自然科学版),2016,44(3):265-271.(LU Chuanteng,HUANG Huacong,QIAN Mingxia.Tidal current and pollutant diffusion characteristucs in spur dike field of north passage in yangtze estuary[J].Journal Of Hohai University(Natural Sciences),2016,44(3):265-271.(in Chinese))
[19]冯丽华.明渠弯道三维水流数值模拟研究[D].扬州:扬州大学,2007.
[20]HIRT C W,NICHOLS B D.A computational method for free surface hydrodynamics[J].Journal of Pressure Vessel Technology,1981,103(2):136-141.
[21]高艳,黄社华,李琼.弯道干流与支流交汇口垂线流速分布的试验研究[J].水电能源科学,2012,30(7):90-93.(GAO Yan,HUANG Shehua,LI Qiong.Experimental research on velocity distribution along depth at junction of bend stream with branch afflux[J].Water Resources and Power,2012,30(7):90-93.(in Chinese))
[22]CIFANI P,MICHALEK W R,PRIEMS G J M,et al.A comparison between the surface compression method and an interface reconstruction method for the VOF approach[J].Computers&Fluids,2016,136:421-435.
[23]王福军.计算流体动力学分析[M].北京:清华大学出版社,2004.
[24]FISCHER H B.On the tensor form of the bulk dispersion coefficient in a bounded skewed shear flow[J].Journal of Geophysical Research:Oceans,1978,83(C5):2373-2375.
[25]ALAVIAN V.Dispersion tensor in rotating flows[J].Journal of Hydraulic Engineering,1986,112(8):771-777.