旋转折射式喷头动能分布规律试验

以圆形及平移式喷灌机常用的Nelson R3000型旋转折射式喷头(绿色喷盘,4流道)为研究对象,应用2DVD测试100、150和200 k Pa工作压力下的水滴粒径和速度,计算并分析了水滴直径与单个水滴动能之间的关系,单位体积水滴动能和动能强度沿射程的变化趋势。结果表明:单个水滴动能与水滴直径的3.65次方呈正比关系,随着至喷头距离的增加,测点单个水滴动能最大值、最小值及平均值增大;距喷头相同测点处,测点单个水滴动能最大值和平均值随着压力的增加而减小;单位体积水滴动能随着至喷头距离的增加呈指数关系增大;距喷头相同测点处,单位体积水滴动能随工作压力的增大而减小,并随着至喷头距离的增大差异增大;距喷头0~6 m范围内,3个工作压力下动能强度均小于0.02 W/m2,且差异较小;6 m至喷洒范围末端,3个工作压力下动能强度出现最大值,分别为0.117 2、0.082 7和0.052 2 W/m2,在距喷头距离相同测点处,动能强度随工作压力升高而减小。

Droplet Kinetic Energy of Rotating Spray-plate Sprinkler

The specific power has often been used in evaluating the influence of water droplet impact on soil surface. A Nelson R3000 rotating spray-plate sprinkler was selected and the drop size, drop velocity were tested under 100,150 and 200kPa by 2DVD.The relationship between drop kinetic energy and drop size, kinetic energy applied per unit drop volume and distances along the sprinkler, specific power and distances along the sprinkler were analyzed. Results indicated that there were proportional relation between the kinetic energy and drop size, and the maximum value of drop kinetic energy from test location increased with the distances along the sprinkler increased. At the same location from the sprinkler, the maximum and average values of drop kinetic energy decreased with the increase of working pressure. The kinetic energy per unit volume increased with the distances along the sprinkler increased, and the change between kinetic energy per unit volume and distances along the sprinkler met exponential function. At the same location from the sprinkler, the kinetic energy per unit volume decreased with the increase of working pressure. At the test location between 0~6m along the sprinklers, the specific power values were less than 0.02W/m2 and the differences were small when operating pressure values were set at 100, 150, 200kPa. At the test location from 6m to the end of the sprinklers, the maximum values of the specific power were 0.1172, 0.0827 and 0.0522W/m2, and the value of the specific power decreased with the increase of working pressure.