扇形面积

计算结果表明当圆形喷灌机输水管布置喷头总数为80～200时，在首末喷头喷出化学液的时间段内，有效喷洒化学液面积约占此时段内总扇形灌溉面积的1/2。

By using the developed equation , a derived result indicated that as the total number of the sprinklers along the lateral ranges from 80 to 200 , the effective chemical area is about one half of the total fan-shaped irrigated area during the time interval .

针对打滑地层孕镶金刚石钻头钻进难题，提出了提高胎体硬度、降低扇形块的面积、加大水口面积的设计思想；

Being aimed at the drilling problems of impregnated diamond bit in slipping formation , a thought of increasing matrix hardness , decreasing area of sector and increasing area of water gap is put forward .

直管排污管的排污阻力小，旋流喷嘴、扇形喷嘴的冲洗面积大、水压高、用水量小。

The straight blow-off pipe has less blow-off resistance , the flushing area of the swirl nozzles and the fan nozzles is large , the water pressure is high , and the water consumption is less .