无压侧管对渠道分水区水力特性影响  

Influence of pressure-free side pipes on hydraulic characteristics in channel diversion zones

作　　者：贾晓萌 吕谋超[1] 王莹莹 张文正[1] JIA Xiaomeng;LYU Mouchao;WANG Yingying;ZHANG Wenzheng(Farmland Irrigation Research Institute,Chinese Academy of Agricultural Sciences,Xinxiang 453002,China;Key Laboratory of Watersaving Irrigation Engineering,Ministry of Agriculture and Rural Affairs,Xinxiang 453002,China)

机构地区：[1]中国农业科学院农田灌溉研究所,新乡453002 [2]农业农村部节水灌溉工程重点实验室,新乡453002

出　　处：《农业工程学报》2025年第4期70-79,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：中央级科研院所基本科研业务费专项(FIRI2022-19);河南省科技攻关项目(232102110290);河南省青年基金项目(242300421469)。

摘　　要：渠道分水区水流流态复杂,易对分流量与泥沙淤积产生影响。因地形、来流量等因素的变化,分水侧管常出现无压状况。为探究无压侧管对渠道分水区水力特性的影响,采用物理模型试验与理论分析相结合的方法,对无压侧管在不同充满度下的主渠分水区三维流速、紊动强度、分水宽度、分流比进行研究。结果表明:自渠底至水面,纵向、横向、垂向流速均呈现出逐渐增大的变化趋势。自分水口上游至下游,纵向平均流速逐渐降低,横向、垂向平均流速先升高后降低;纵向、横向、垂向紊动强度先升高后降低,且在正对管道入口区域紊动强度较大。随着管道充满度的增大,主渠各断面纵向平均流速与紊动强度、垂向平均流速降低,横向平均流速与紊动强度、垂向紊动强度升高。分水宽度随着充满度的增大而增大,当充满度小于0.5时,分水宽度自水面向下逐渐减小,当充满度大于0.5时,分水宽度自水面向下先增大后减小。当主渠流量一定时,分流比随充满度的增大而增大;当充满度一定时,随着主渠流量的增大,分流比减小。研究成果可为田间渠管引水工程设计与维护提供一定的技术支撑。A diversion port is often constructed on the side of the main channel for drainage.The water flow can be diverted from the channel into the field for irrigation.A curved water flow is usually formed when the water flows from the channel into the diversion port.In addition,the sudden contraction of the diversion port section can cause a drastic variation in the flow state of the water in the diversion area,thus forming outstanding high-speed and low-speed zones.This uniform distribution of flow velocity can have a great impact on the diversion flow rate and sediment distribution.The water distribution of side pipes can often experience a state of free pressure,due to the variation in the flow rate and pipe diameter.This study aims to investigate the influence of free-pressure side pipes on the hydraulic characteristics of the channel diversion zone.A series of physical model experiments were conducted to determine the three-dimensional flow velocity,turbulence intensity,diversion width,and diversion ratio of the channel diversion zone under different filling degrees.The experimental results indicate that there was no variation in the distribution of three-dimensional flow velocity and turbulence intensity at the channel separation zone under different filling degrees.But the free-pressure pipe flow posed a great influence on the magnitude of the three-dimensional flow velocity and turbulence intensity.Furthermore,the longitudinal,transverse,and vertical flow velocities all shared a gradually increasing trend from the bottom of the canal to the water surface.The longitudinal average flow velocity gradually decreased from the upstream to the downstream of the water outlet.While the transverse and vertical average flow velocities first increased and then decreased.The longitudinal,transverse,and vertical turbulence intensity first increased and then decreased.The turbulence intensity was higher in the area directly at the pipeline inlet.There were relatively high horizontal and vertical flow velocities at the diversi

关 键 词：灌溉 管道 渠道 无压 三维流速 分水宽度 分流比 

分 类 号：S126[农业科学—农业基础科学]