搜索结果: 1-8 共查到“农业工程 Drip irrigation”相关记录8条 . 查询时间(0.128 秒)
Survey of soil water distribution in a vineyard and implications for subsurface drip irrigation control
gravimetric water content Sentek Diviner spatio-temporal variability volumetric water content
2016/8/2
Controlling a subsurface drip irrigation system based on soil water monitoring is a very efficient way to supply grapevines with water for optimal thriving and high vintage quality. However, finding a...
三角绕流滴灌灌水器结构设计和优化（Structural Design and Optimization of Triangle Circulation Drip Irrigation Emitters）
灌水器 三角绕流 水力性能
2010/12/28
以三角绕流滴灌灌水器结构的流道单元为研究对象，利用Pro/E软件完成灌水器造型设计，结合计算流体动力学软件Fluent 6.3模拟分析流道的水力性能，研究此类灌水器的湍流特性，揭示其内部湍流流动机理，并对流道结构进行优化。根据分析结果，通过改变外部大三角的形状与内部小三角的形状和位置，对流道单元进行结构优化，得出一种流态指数小于0.5，流道内速度分布均匀，流量在滴灌允许范围内，抗堵性能优良的三角绕...
基于CAD的滴灌系统水力自动计算模型（Hydraulic Analysis Model in a CAD System for the Design of Drip Irrigation）
滴灌 水力计算 计算机辅助设计
2009/5/22
针对滴灌CAD系统中水力计算与管网布置的耦合问题，研究了管网图形识别及有效性判定，并基于AutoCAD二次开发思想，应用步进法水力学解析原理，建立了滴灌系统计算机辅助设计水力计算模型，有效地将管网图形与水力计算耦合，使水力计算结果及时反馈到管网图形中，为实际工程管网水力性能的优化提供了技术手段。通过算例对该模型进行了验证，结果表明，应用该模型计算出的流量和水头偏差率均在允许范围内，管网识别及水力计...
土壤质地对地下滴灌灌水器水力要素的影响（Effect of Different Textural Soils on Hydraulic Characteristics of Emitters under Subsurface Drip Irrigation）
地下滴灌 灌水器 土壤质地
2009/5/19
为研究不同质地土壤中灌水器水力要素的变化规律及其差异，选取灌水器工作压力、土壤容重和土壤初始含水率为因素，分别在粘土、壤土和砂土中采用混合水平均匀设计安排试验。试验结果表明，不同土壤中的灌水器出流规律一致：即当工作压力不变时，灌水器流量在灌水初期略大，而后减小并趋于恒定，这个变化过程仅1～2min；在相同压力下，地下滴灌灌水器流量比地表滴灌小5%～20%，压力越大，二者越接近；灌水器流量随工作压力...
虚拟节点有限元法解析滴灌支管水力学计算（Finite Element Method for Hydraulic Design of Drip Irrigation Submain Units with Virtual Emitter System）
滴灌 支管单元 有限元法
2009/5/19
滴灌支管和毛管组成的支管单元的水力学计算是滴灌管网水力学设计的关键环节。运用虚拟节点有限元法和虚拟节点平均水头损失有限元法解析支管单元的水力学计算，可以计算出支管和每根毛管的水头损失，同时显著减少计算量，研究结果为包含几十万乃至上百万个滴头的滴灌系统水力学设计提供了新的方法。
Effects of Different Irrigation Programs on the Growth of Cotton Under Drip Irrigation
Drip irrigation Growth of cotton plant Leaf area index (LAI)
2009/1/14
This study was conducted to determine of effects the cotton plant growth of different irrigation programs in a drip system. The amount of water applied was based on free surface evaporation from a scr...
Development of a Mathematical Model Using Dimensional Analysis for Predicting the Friction Losses in Drip Irrigation Laterals with Cylindrical Type In-Line Emitters
Drip irrigation emitters friction loss mathematical model dimensional analysis
2009/1/13
This paper presents a prediction model developed using dimensional analysis for friction losses in drip irrigation laterals. Drip irrigation laterals with cylindrical type in-line emitters placed at d...
Water Application Uniformity of a Subsurface Drip Irrigation System at Various Operating Pressures and Tape Lengths
Subsurface drip irrigation emitter discharge uniformity coefficient emitter performance
2009/1/9
Subsurface irrigation has been the focus of attention mainly because of its low evaporation rate and deep percolation losses. Uniformity of water applications and its stability, however, are still a m...