滴头流道内部含沙水流流动特征的试验研究

Experimental study on sediment flow hydraulic characteristics in dripper emitter path

滴头流道中水流的运动状况是影响滴头水力性能的主要因素,而水源中悬浮颗粒(沙粒)的存在对于水流有着不可忽略的反作用。该文研究了浑水(含沙水流)在迷宫滴头流道内流动过程,分别选用清水和含沙浓度为40、80、160 mg/L的浑水,通过滴头在不同压力下流量变化,分析了流道内部含沙水流流动特征及沙粒对滴头水力性能的影响。试验结果表明:同一工作压力下,沙粒的制紊效应使得滴头流量随悬浮颗粒浓度的加大先上升后下降;滴头的流态指数随悬浮颗粒浓度的提高略呈下降趋势;在该试验条件下,流道内层流向湍流过渡早于常规流动,工作压力在45 kPa时流道内水流已处于湍流状态。

The hydraulic property of emitters is primarily influenced by the flow movement of emitter path. The reaction of the suspend particles to the flow is intense and should not be ignored. The flow process of flow with sand particles in labyrinth emitter path was studied. The mass fractions of sand particles in the experiment were 40, 80, 160 mg/L, respectively. The flow rates were measured both cleaning water and flow with sand particles. Effects of flow friction characteristics and sand particle on the hydraulic property of emitters were analyzed. Results indicate that the emitter discharge decreases slightly and the emitter flow rates show a trend from rising to declining with the increasing of the suspension concentration in the same operating pressure because of the turbulence prevention by sands. The transition from laminar flow to turbulent flow in emitter path happened earlier than that in normal sized tube. The critical pressure is about 45 kPa.