滩地植被化的复式断面明渠均匀流的流速比

Velocity ratios of vegetated floodplain compound channel uniform flow with submerged stems

采用量纲分析法得到了淹没滩地植被化复式断面渠道中主槽和滩地间表观切应力的基本形式,基于Thornton等的实测资料,运用最小二乘法导出了表观切应力中动量传输系数的计算式.在计算动量传输系数中考虑了滩地与主槽水深比、宽度比以及植被阻水百分数等因素的作用,进而采用力的平衡原理,给出了主槽和滩地的流速和流量的计算公式.该公式反应了动量传输系数及主槽糙率、滩地糙率和植被密度对流速流量的影响,计算结果与实测资料符合良好.

The equation of apparent shear stress from vegetated floodplain compound channel flow with submerged stems was gotten by dimensional analysis.Based on the experimental data of apparent shear stress given by Thornton,the momentum transfer coefficient in the equation of apparent shear stress was obtained by least-square principle analysis.The effect of relative water depth,relative width and percent flow blockage caused by vegetation on the momentum transfer coefficient was considered.The velocity and discharge formulas were derived from force balance principle.The influence of momentum transfer coefficient,main channel roughness,flood plain roughness,vegetation density on the velocities and discharges are considered in these formulas.The experimental data was used to verify these formulas.It is found that the calculated results are in good agreement and are shown the validity of these formulas.