沟灌侵蚀过程的水动力学特性模拟研究

Simulation Study on Hydraulic Characteristics of Furrow Irrigation Erosion

通过室内沟灌侵蚀模拟实验,研究了沟灌侵蚀过程中不同流量、坡度下垄沟水流的流态、流速及阻力系数的变化规律。结果表明,坡度和流量对水流流速的影响显著,流速随着坡度和流量的增大呈逐渐增大的趋势;流速与坡度、流量的相关性显著。垄沟水流的雷诺数变化范围为923～4 623,属于紊流;并且随着流量的增大呈现出逐渐增大的规律。弗汝德数在实验过程中变化范围为0.41～1.34,大部分都处在急流状态;坡度的增大使弗汝德数也随之增大。阻力系数变化范围为0.14～0.53。

Abstract： In order to study the erosion process from perspective of kinetics and provide scientific basis for furrow irrigation erosion forecast model, the simulated tests of furrow irrigation erosion were made in laboratory to study the hydraulic characteristics of irrigation runoff including Reynolds, Froude and Roughness coefficient under the different slopes and flow rates. The results showed： the flow and the slope had a deep impact on flow rate. The flow rate increased with the increase of the slope and flow. Reynolds number varied from 923 to 4 623, which indicated that the flow belonged to the turbulence, and the Reynolds number increased with the increase of flow. The Froude number varied from 0.41 to 1.34,most of which was supercritical flow, and the Froude number increased with the slope increasing. The Roughness coefficient varied from 0.14 to 0.53.