沉水植物作用下垂线平均水流挟沙力计算公式  

Formula of depth‐averaged suspended sediment transport capacity in submerged vegetation flow

作　　者：郭蔓 李达 杨中华[1] 孙昭华[1] GUO Man;LI Da;YANG Zhonghua;SUN Zhaohua(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《武汉大学学报（工学版）》2023年第5期524-531,共8页Engineering Journal of Wuhan University

基　　金：国家自然科学基金重点国际(地区)合作研究项目(编号:52020105006);江西省水利科技项目(编号:202224ZDKT25)。

摘　　要：基于维持泥沙悬浮的能量(悬浮功)来源于水流紊动能的观点,将悬浮功作为汇项引入立面二维的沉水植物作用下明渠水流紊动能方程,即认为冲淤平衡条件下水体所产生的紊动能分别用以维持泥沙悬浮和黏性耗散。在无植物明渠中水体产生紊动能的固定比例部分用以维持泥沙悬浮,但是沉水植物的存在使得黏性耗散项增加,该比例减小且不再为定值。通过引入以无植物明渠尺度为基准的等效比值系数表示耗散项对于该比例的影响,从而分离出固定的比例系数,推导出沉水植物作用下垂线平均水流挟沙力计算公式。采用试验资料进行验证,结果显示计算值与实测值平均相对误差为10.02%,表明该公式能较好地确定沉水植物作用下的水流挟沙力。This paper introduces suspension work to the turbulent kinetic energy(TKE)equation(k-equation)in fully developed steady two-dimensional submerged vegetated open channel flow as a sink term.That is to say,it is assumed that the production of TKE is used to maintain sediment suspension and viscous dissipation respectively under the condition of scour and silt equilibrium.In the open channel without vegetation,a fixed proportion of the TKE produced is used to maintain the sediment suspension,but the presence of submerged vegetation increases the viscous dissipation term,the proportion decreases,and it is no longer a constant.An equivalent ratio coefficient based on the scale of open channel without plants is introduced to represent the influence of dissipation term on this proportion,so as to separate the fixed equivalent proportional coefficient,and deduce the calculation formula of vertically averaged sediment carrying capacity under the action of submerged plants.The formula is verified by flume experimental data,and the mean relative error between the calculated and measured values is 10.02%,which shows this formula can determine the sediment carrying capacity of water flow under the action of submerged vegetation well.

关 键 词：沉水植物 水流挟沙力 悬浮功 紊动能 

分 类 号：TV142.3[水利工程—水力学及河流动力学]