滴灌灌水器迷宫式流道内部流体流动特性分析与试验研究

选取目前中国农业灌溉领域中最为典型的六种迷宫式流道滴灌管，利用精密读数显微镜与AutoCAD技术相结合的测量方式测定了流道几何参数，利用自行研制的灌水器水力性能测试平台测量了六种滴灌灌水器在不同压力条件下的自由出流流量，并研究了灌水器流道内部的流动特性。结果表明：低压运行对灌水器的水力性能有一定影响，但不显著；流道断面统计平均流速在0．08—0．90m／s之间；迷宫式流道内部流体流动的雷诺数R,为105—930，层流和紊流的流态转捩的临界雷诺数比常规尺度流道的值要小，低于255。

Experimental study on flow characteristics in labyrinth path emitters

The geometric parameters of the flow path of current used six kinds of labyrinth emitter for trickle irrigation are measured by means of high-precision microscope combining with AutoCAD technology and the hydraulic performances of these emitters are tested on the test stand developed by the authors. On this basis, the characteristics of flow in paths are analyzed in detail. The research results show that the performance of emitters operated under low pressure will be reduced, but the influence is insignificant.The statistical average velocity in the paths is in the range from 0.08m/s to 0.90m/s. The critical Reynolds number for flow transition from laminar flow to turbulent flow is 255.