Effect of Rotation Speed of Micro-sprinklers on Hydraulic Performance

An experimental study was conducted to asses the effect of rotation speed on hydraulic performance of rotating micro-sprinklers.The results indicate that the damping grease can notably decrease the rotation speed,under 100~250 kPa pressure,the micro-sprinkler rotation speed decreases from 2230~4225 r/min without damping grease to 0.1~1.1 r/min with all the damping grease;comparing with high rotating speed,the throw distance of 1.8 mm nozzle microsprinkler in low rotation speed increases by(20.5%)~31.8% under 100~250 kPa pressure,while during the low rotation speed zone,the throw distance change vary little,At 200 kPa pressure,when the rotation speed of 1.8 mm nozzle micro-sprinklers increases from 0.41 r/min to 6.1 r/min,the throw distance decreases only by 4.4%;The distribution rate curve of slow-rotating micro-sprinklers is more like triangle than that of high rotating ones.