摘要
为解决坡地喷灌水量分布实测困难的问题,该文基于弹道轨迹方程,考虑水滴运动蒸发,通过三维坐标系降维转化,计算坡地喷灌水滴空间运动轨迹,以平地实测水量分布为基础,根据水量平衡原理,建立坡地喷灌水量分布计算模型。结果表明,实测与模拟的水量分布、射程的相对误差小于9%和5.04%,说明建立的模型能够准确反映坡地喷灌水量分布规律,具有一定的可靠性,可应用于坡地喷灌系统设计。以雨鸟LF1200喷头为研究对象,应用模型重点分析地形坡度、喷头布置方式、间距和工作压力等因素对喷灌均匀度的影响,结果表明,在95%的置信度下,地形坡度、喷头工作压力、布置方式和间距对喷灌均匀度的影响均呈显著水平,其中喷头工作压力影响最大,布置方式和喷头间距影响次之,地形坡度影响最小,且在一定坡度范围内,地形坡度对喷灌均匀度的影响远小于工作压力、喷头布置方式和间距。在坡地喷灌系统设计时,如果选用雨鸟LF1200喷头,须保证喷头在正常工作压力下运行,不宜低压作业,应优先考虑方形布置,在兼顾系统成本和喷灌质量时,建议喷头间距宜为其平地射程的0.8倍,且喷头不宜在15°以上的坡地作业。研究可为坡地喷灌系统规划设计提供参考。
Limited by experimental conditions, the water distribution of sprinkler irrigation on sloping land is difficult to measure. In order to solve this problem, ballistic theory and the model for evaporation of droplets were used to calculate the trajectory of the spray water droplet. On the basis of the measured water distribution of one radial leg on flat ground, and using the translation of coordinates from three-dimensional space to two-dimensional space, a simulation model for calculating the water distribution of sprinkler in sloping field was proposed. A custom computer software script was developed using Eclipse software to implement the method to a case study. The software could calculate water distribution at different sloping lands when the operating environment and hydraulic parameters of the sprinkler were given. Three- dimension triangulation interpolation model was applied in order to get the grid data of single sprinkler water distribution, and the grid data were used to calculate the uniformity of different sprinkler spacing with square and triangular lattice configuration. Measured and simulated values were compared for the water distribution and spray distance to validate the accuracy of the software on 2.86°, 5.71° and 8.53° sloping land using Rainbird LF1200 sprinkler. The results revealed that the simulated and measured water distribution and jet distance had the maximum relative errors of 9% and 5.04%, indicating that the model could be well used to simulate the water distribution for sprinkler on sloping land. The model could be directly applied in the design of sprinkler irrigation system in sloping field. The effects of slopes, square and triangular sprinkler layout, sprinkler spacing and operating pressure on water application uniformity were analyzed for the Rainbird LF1200 sprinkler using the simulation model. Furthermore, effects of 4 factors（pressure, layout, spacing, and slope） on water uniformity were evaluated. The results showed that the sprinkler operating pressure greatly af
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2016年第13期59-66,F0003,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(51409244)
"十二五"农村领域国家科技计划课题(2015BAD22B01-02)
西北农林科技大学基本科研业务费专项资金项目(2014YB061)
关键词
模型
灌溉
压力
坡地喷灌
水量分布
均匀度
models
irrigation
pressure
sprinkler irrigation on sloping land
water distribution
uniformity
