水保所知识产出(1956---)知识库

采用基于三维视频粒子测量原理的视频雨滴谱仪( Two-dimensional video disdrometer，2 DVD) 对喷灌机中常用
的Nelson D3000 型喷头在多个工作压力下水滴直径沿射程的分布进行了测量，分析了水滴直径沿射程的变化趋势
及水滴速度、水滴角度与水滴直径之间的关系。结果表明: 水滴直径与射程符合指数函数关系，在距离喷头相同测
点处，水滴直径随工作压力的升高而减小，而射程末端的水滴直径随着压力的升高而增大; 水滴速度随水滴直径增
加而增大，两者呈对数关系; 水滴落地时与地面夹角( 简称水滴角度) 随水滴直径增加呈减小趋势，水滴直径小于
1. 0 mm 时， 50、100、150 和200 kPa 工作压力下，与地面夹角为90°的水滴个数占总水滴数的比值分别为90. 46%、
84. 46%、89. 91%和89. 15%，其余水滴与地面夹角在30° ～ 89°之间，水滴直径在1. 0 ～ 2. 25 mm 范围内，水滴角度
随水滴直径的增加迅速减小，水滴直径大于2. 25 mm 时减小趋势变缓，4
个工作压力下最大直径水滴落地时与地面
夹角平均值为45°; 工作压力对于水滴直径与速度、水滴直径与角度之间的关系影响较小。

A two-dimensional video disdrometer ( 2DVD) was used to measure drop size，drop velocity
and drop angle from Nelson D3000 spray-plate sprinklers with a 4. 78 mm nozzle and operating pressure of
50，100，150，200 kPa． The relationship among drop sizes，drop velocity and drop angle were analyzed．
Ｒesults indicated that the relationship between drop diameter and distances along the sprinkler met
exponential function． The volumetric mean diameter increased with the distance along the sprinkler
increased，and at the same location from the sprinkler the average droplet diameter decreased with the
increase of working pressure． The relationship between drop velocity and drop diameter met logarithmic
function． Drop velocity increased with the drop diameter increased，and the effect of operating pressure
on the relationship between drop diameter and velocity was not obvious． Drop angle decreased with the
increase of drop diameter． When drop diameter was smaller than 1. 0mm and operating pressure was at
50，100，150，200 kPa，90. 46%，84. 46%，89. 91% and 89. 15% of the droplets descended
perpendicularly to the ground，respectively． The rest of the droplets descended to the ground with angle
between 30° ～ 89°． When drop diameter was between 1. 0 mm and 2. 25 mm，the drop angle decreased
rapidly with the drop diameter increased． And when drop diameter was greater than 2. 25 mm，the
decrease trend became slower． The relationship between drop angle and drop diameter met a good linear
function，and the effect of operating pressure on the relationship between drop angle and diameter was not
obvious．