检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
机构地区:[1]西北农林科技大学机械与电子工程学院,陕西杨凌712100 [2]西北农林科技大学水土保持研究所,陕西杨凌712100
出 处:《农业机械学报》2014年第12期56-61,共6页Transactions of the Chinese Society for Agricultural Machinery
基 金:新世纪优秀人才支持计划资助项目(NCET-12-0473);'十二五'国家科技支撑计划资助项目(2011BAD29B08);高等学校学科创新引智计划(111计划)资助项目(B12007)
摘 要:利用2D视频雨滴谱仪,对喷头喷洒的雨滴形状、尺寸分布、平均直径和垂直降落速度等进行准确测量,分析了喷嘴直径、工作压力对雨滴平均直径变化趋势的影响,建立了雨滴平均直径与垂直降落速度间的关系模型。结果表明:人工模拟降雨系统下喷头喷洒雨滴的直径范围在0-3 mm;在相同喷嘴直径下,随着工作压力的增大,雨滴平均直径呈下降趋势;在工作压力不变的条件下,随着喷嘴直径的增大,雨滴平均直径会随之增大;通过雨滴平均直径与垂直下落速度间的关系模型,能够较好地预测雨滴的降落速度。In the water-saving irrigation,the characteristics of sprinklered raindrops is an important standard of nozzles hydraulic performance. The paraments which can reflect the characteristics of raindrops mainly contain drop diameter,drop size distribution,drop velocity and raindrop kinetic energy,in all of this parameters,the raindrop diameter is the basis of other parameters studies. This paper makes accurate measurements of drop view,drop size distribution,equi-volumetric diameter and vertical velocity of raindrops by using 2D-video-distrometer. It also analyses the trend on raindrop equi-volumetric diameter affected by nozzle size and working stress,and establishes a model based on the relationship of raindrop equi-volumetric diameter and the vertical velocity. The results show that the equi-volumetric diameter of artificial rainfall sprinklers raindrop is ranged from 0 to 3mm and when the working pressure increased,the equi-volumetric diameter of raindrops decreased as the sprinklers size is not changed; on the contrary, when the working pressure is changeless, the equi-volumetric diameter of raindrops increased as the sprinklers size increased. According to the relationship model of equi-volumetric diameter versus vertical velocity of raindrops,it can get of good prediction of the vertical velocity which may provide a fundamental basis for kinetic energy calculation and establishing the mathematical models of erosion forecasting.
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.3