迷宫流道断面形状对灌水器水力性能的影响

Influnce of Section Shapes of Labyrinth Channels on the Hydraulic Performance of Emitters

为研究矩形迷宫流道断面形状对灌水器水力性能的影响,利用软件FLUENT6.1软件对5种流道断面形状不同的矩形迷宫流道内水流运动进行数值模拟,通过模拟得到的灌水器压力～流量关系和灌水器内水流流速分布分析得出:1)流量系数、流态指数均与断面湿周呈正相关,断面湿周越大流量波动性及对压力的敏感程度越大;2)流道断面湿周较小的L1型迷宫灌水器其流态指数小于其它4种,小于0.57,说明该灌水器内水流为紊流,其压力补偿性较高;3)灌水器流道内水流具有重复性;4)流道断面形状对灌水器内水流流速分布不会产生较大影响。因此,在灌水器流道断面为矩形且面积相同的情况下,流道断面为正方形的灌水器的水力性能要优于其它断面形状的灌水器,且流道断面湿周越小,灌水器的压力补偿性越高,系统灌溉均匀度越高。

The research studied the influnce of section shapes of labyrinth channels on the hydraulic performance of emitters.The paper deals with the numerical simulation of fluid in five rectangle labyrinth channels with different section shapes using software Fluent 6.1 and offers the analysis of the relationship of flux and pressure,the velocity distribution of the labyrinth channels section：1）The results showed positive relationship between wetted perimeter and discharge coefficient and flow state exponent.With the increasing of the wetted perimeter of labyrinth channels section,discharge fluctuaty and pressure sensitivity are increasing ;2）The flow state exponent of the L1 emitter is not only smaller than other four emitters,but also is smaller than 0.57.It is show that the current is turbulent in L1 emitter.It has better pressure compensation;3）The current of labyrinth channels has repeatability;4）The labyrinth channels section do not cause significan influence to the velocity distribution on labyrinth channels sections.When rectangle channels have the same area,the hydraulic performance of square channels are better than other channels.Moreover,the smaller the length of wetted perimeter is,the better the emitter pressure compensation and uniformity of drip irrigation system.