典型文献
Flocculation properties of cohesive fine-grained sediment in the Three Gorges Reservoir under variable turbulent shear
文献摘要:
Sediment flocculation is a key process for the deposition of fine-grained sediments in the Three Gorges Reservoir(TGR)of China.Sediment flocculation influences the evolution of the river regime,but also hampers the smooth navigation in the long term.However,the flocculation process and its controlling factors are poorly understood.We experimentally determined the flocculation properties of cohesive sediment of samples from the TGR(predominantly a mixture of clay and silt)over a range of turbulent shear rates and sediment concentrations.The experiments were conducted in an almost isotropic turbulence field,which was simulated by an array of horizontal oscillating grids in a water tank.Sediment flocculation was recorded by a camera and investigated by image analysis.Our new data indicate that flocculation is generally a response in equilibrium median floc size(df,50)to the increase of the shear rate G.The peak value is attained at G = 16.5 s-1,where df,50 is 81.3 pm(for the suspended sediment concentration(ssc)= 0.4 g/L)and 107 pm(for ssc=0.7 g/L),respectively.At low shear rates(G<16.5 s-1),the equilibrium floc sizes df,50 increase with rising shear rate G and is inversely related to the Kolmogorov micro length scale η.We attribute this variability to an insufficient deposition time of the sediment flocs in the water tank.Settling velocities,calculated from our experimental data of the floc sizes,are almost consistent with in-situ measured settling velocities,and are ten times larger than the terminal settling velocity of primary particles as calculated from Stokes'law.
文献关键词:
中图分类号:
作者姓名:
LIU Jie;SHEN Ying;WANG Xin
作者机构:
National Inland Waterway Regulation Engineering Research Center,Chongqing Jiaotong University,Chongqing 400074,China;Tianjin Research Institute for Water Transport Engineering,Tianjin 300000,China;National Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China
文献出处:
引用格式:
[1]LIU Jie;SHEN Ying;WANG Xin-.Flocculation properties of cohesive fine-grained sediment in the Three Gorges Reservoir under variable turbulent shear)[J].山地科学学报(英文版),2022(08):2286-2296
A类:
Flocculation
B类:
properties,cohesive,fine,grained,Three,Gorges,Reservoir,variable,turbulent,shear,Sediment,flocculation,key,process,deposition,sediments,TGR,China,influences,evolution,river,regime,also,hampers,smooth,navigation,long,However,its,controlling,factors,are,poorly,understood,We,experimentally,determined,samples,from,predominantly,mixture,clay,silt,over,range,rates,concentrations,experiments,were,conducted,almost,isotropic,turbulence,field,which,was,simulated,by,array,horizontal,oscillating,grids,water,tank,recorded,camera,investigated,image,analysis,Our,new,data,indicate,that,generally,response,equilibrium,median,df,increase,peak,value,attained,where,pm,suspended,ssc,respectively,At,low,sizes,rising,inversely,related,Kolmogorov,micro,length,scale,attribute,this,variability,insufficient,flocs,Settling,velocities,calculated,our,consistent,situ,measured,settling,times,larger,than,terminal,velocity,primary,particles,Stokes,law
AB值:
0.539394
相似文献
机标中图分类号,由域田数据科技根据网络公开资料自动分析生成,仅供学习研究参考。