【摘要】 为了从理论上分析下渗对坡面流动力学参数的影响,基于Navier-Stokes方程,将坡面流视为平面恒定非均匀流,考虑下渗影响,推导出缓坡、陡坡坡面流断面速度分布,探讨了下渗对坡面流雷诺数、沿程阻力系数、滚波波幅的影响,基于相关试验资料对理论分析结果进行了验证.结果表明,缓坡条件下,坡面流流态为层流或紊流,试验过程中有必要区分初渗、稳渗阶段判别流态.陡坡条件下,不同下渗率及水深的坡面流均为紊流.坡面流黏性影响厚度接近水深或大于水深,不会产生类似明渠水流的外流势流区域.同时考虑下渗和表面张力作用,沿程阻力系数与雷诺数成反比.滚波波幅受水深、下渗率、水流运动黏度、坡降的影响.该研究结论为坡面水流运动特性试验研究及理论分析奠定了一定基础.更多还原

【Abstract】 To analyze the theory of the influence of infiltration on the depth of the viscous sub-lay and kinetic parameters of shallow open channel flow on a slope,based on the Navier-Stokes equation,the flow velocity distributions of gentle slope and steep slope werederived.With the results,the influence of the infiltrate on the rate of the Reynoldsnumber,Froude number,friction resistance coefficient,and rolling wave amplitude werestudied under the conditions of slope planar steady non-uniform flow.The analysisresults have been matched to the related experimental data.Results show that thelaminar flow or turbulent flow appears under the flat slope condition caused by theinfiltration rate,the flow velocity and depth,and the fluid type likely to be mainlyassociated with the process of influence between the initial permeability and steadyseepage stage in the test.The fluid type is turbulent under the abrupt slope conditionwith a different infiltration rate and flow velocity and flow depth.On a flat slope orabrupt slope,the depth of viscous sub-lay is closer to or greater than the water depth;even if the infiltration rate was very small,and the depth of the viscous sub-lay increasedwith the increase of the kinematic viscosity coefficient but decreased with the increase ofthe infiltration rate,it would be impossible to see irrotational flow similar to openchannel flow.The frictional resistance coefficient has a positive relationship with theReynolds number,considering the capillary force and the infiltration rate influence.Theinfluence factors of the rolling wave amplitude include the flow depth,infiltration rateand viscosity of water flow and the grade.The conclusions of this study provide a basisfor experiment and theory studies on the shallow open channel flow of a slope.更多还原