动态水压对坡地喷灌水滴直径分布的影响

【Objective】To explore the distribution law of water droplet diameter when using dynamic water pressure sprinkler irrigation on slopes. 【Methods】Taking the Rain Bird R5000 sprinkler head as the research object, the video disdrometer was used to measure the along-path distribution of water droplet diameter in slope sprinkler irrigation. The changes of water droplet diameter along the range, the frequency distribution of water droplet diameter, and the relationships between the velocity and angle of landing water droplets and the water droplet diameter under dynamic water pressure and constant pressure modes were analyzed respectively, and the similarities and differences of the above relationships under the two pressure modes were compared. 【Results】①There are differences in water droplet diameter between dynamic water pressure and constant pressure sprinkler irrigation. As the distance from the sprinkler head increases, the difference between the two gradually increases; while as the slope increases, the difference between the two becomes smaller. ②The number of small water droplets accounts for the vast majority near the sprinkler head and at the end of the range. ③The average velocity of water droplets increases logarithmically with the water droplet diameter, and the pressure mode and slope have no significant effect on the relationship between velocity and diameter. ④The frequency of vertically landing water droplets is closely related to the distance from the sprinkler head, and the diameter of vertically landing water droplets is small, and the influence of the pressure mode on the relationship between angle and diameter is not obvious. 【Conclusion】On slopes, when using dynamic water pressure and constant pressure sprinkler irrigation respectively, the distribution laws of water droplet diameter of the two are similar, and dynamic water pressure will not cause more adverse effects on slope sprinkler irrigation and can be applied in production practice.

【目的】探索坡地上采用动态水压喷灌时水滴直径分布规律。【方法】以雨鸟R5000型喷头为研究对象,应用视频雨滴谱仪对坡地喷灌水滴直径沿程分布进行了测量,分别分析了动态水压和恒压模式下水滴直径沿射程变化、水滴直径频率分布及落地水滴速度、水滴角度与水滴直径之间的关系,并比较2种压力模式下上述关系的异同。【结果】①动态水压和恒压喷灌下水滴直径存在差异,随距喷头的距离增加,二者差异逐渐增大;而随坡度增大,二者差异变小。②在喷头附近和射程末端处小水滴数量占绝大多数。③水滴平均速度与水滴直径呈对数增长,压力模式和坡度对速度与直径之间的关系不显著。④垂直落地的水滴频率大小与距喷头距离关系密切,且垂直落地水滴直径较小,压力模式对角度与直径关系的影响不明显。【结论】在坡地上,分别采用动态水压和恒压喷灌时,二者水滴直径分布规律相似,动态水压不会对坡地喷灌造成更不利影响,可应用于生产实践。