摘要
引黄喷灌水源含沙量大,容易造成冲蚀磨损导致喷头结构变形,进而引起喷灌系统灌溉质量的降低。为了研究折射式喷头的冲蚀磨损规律,采用室内试验与数值仿真相结合的方法,对不同工况下的冲蚀位置和冲蚀速率进行分析,验证了数值模拟具有较高的准确性,在此基础上,采用回归分析的方法,分别研究了锥角高度、流道长度与进口流速、含沙量和喷灌历时的关系。结果表明,喷头的冲蚀主要集中于蓝色喷盘的锥角处、流道与分水台凸起处;喷头的冲蚀速率随进口流速增大而增加;随着喷灌历时的增加,喷盘锥角高度不断下降,当进口流速从9.87 m/s增加到21.65 m/s时,48 h喷灌时间内喷盘锥角高度从2.80 mm分别下降到2.48、2.39、2.32、2.25和2.23 mm,最大下降幅度为20.36%;随着进口流速的增大,流道长度在磨蚀作用下逐渐减小,从10.50 mm分别减小到8.88、8.30、7.82、7.71和7.11 mm,最大减小幅度为32.29%;喷盘的锥角高度及流道长度与时间存在线性关系。数值模拟方法可用于研究折射式喷头的冲蚀规律,为喷头的失效预测提供参考。
The water source of Yellow-river diversion irrigation has a high sediment content,which can cause erosion and wear,leading to structural deformation of sprinkler head,and resulting in a reduction of irrigation quality of sprinkler system.To study the erosive wear law of refracting sprinkler,this paper combined laboratory testing and numerical simulation to analyze the erosive position and rate under different working conditions,and to verify the high accuracy of numerical simulation.On this basis,the relationship between cone angle height,runner length,inlet flow rate,sand content and sprinkler duration were studied by using regression analysis.The results indicate that the erosion of the sprinkler is primarily concentrated in the cone corner of the blue spray disc,the bulge of the flow channel,and the water distribution platform.The erosion rate of sprinkler increases with the increase of inlet velocity.With an increase in irrigation duration,the cone angle height of spray disc decreases continuously.When the inlet flow rate increases from 9.87 m/s to 21.65 m/s,the cone angle height of spray disc decreases from 2.80 mm to 2.48 mm,2.39 mm,2.32 mm,2.25 mm and 2.23 mm in 48 h irrigation time,representing a decrease of 20.36%.With the increase of inlet velocity,the length of passage decreases gradually due to abrasion,from 10.50 mm to 8.88 mm,8.30 mm,7.82 mm,7.71 mm and 7.11 mm,respectively,representing a decrease of 32.29%.There is a linear relationship between the height of the cone angle and the length of the runner and time.The numerical simulation method can be used to study the erosion rule of the refraction sprinkler and provide a reference for the failure prediction of the sprinkler.
作者
李俊龙
李杰
张以升
LI Jun-long;LI Jie;ZHANG Yi-sheng(School of Water Conservancy and Civil Engineering,Zhengzhou University,Zhengzhou 450001,China)
出处
《节水灌溉》
北大核心
2023年第7期84-89,共6页
Water Saving Irrigation
基金
国家自然科学基金项目(52279028)。
关键词
折射式喷头
冲蚀磨损
数值模拟
冲蚀速率
几何结构
refraction sprinkler
erosion wear
numerical simulation
erosion rate
geometric structure
