工作压力对滴灌管迷宫流道灌水器水力性能的影响

降低滴灌系统灌水器工作压力有望成为减少滴灌系统能耗以及运行费用的一种有效途径，但目前低压灌水器还十分少见。基于此，选取了国内应用较为广泛的5种典型迷宫流道灌水器，分析了不同工作压力区间对灌水器水力性能及消能特征的影响。结果表明：5种灌水器在低压条件下运行对于灌水器流量系数Kd和流态指数x具有一定影响，但对于流态指数x的影响未达显著水平。同一流道类型的灌水器流量系数Kd与无量纲数A/L2呈显著的线性相关关系，不同流道类型之间差异显著。5种灌水器流道内流态为紊流，未发生流态转捩行为，采用常规管道流态转捩雷诺数2200去判断流道内流态是不合适的。

Effects of working pressure on hydraulic performances of labyrinth path emitters

To decrease working pressure of drip irrigation emitter may become an efficient way of decreasing energy consumption and operating cost, but there are few emitters working under low pressure at present. Based on this, the products of 5 typical widely-used labyrinth path emitters were studied in the paper. The effects of different working pressures on hydraulic performances and energy dissipation characteristics of emitters were analyzed. The results showed that low pressure had some effect on flux coefficient and flow regime index, but the effect on flow regime index was insignificant. Flux coefficient of the same structure had prominent linear correlation with A/L2, which is a dimensionless number. However, flux coefficients of different flow paths had varied wildly. The flow states of 5 flow paths were turbulent flow with no flow transition. It was not appropriate to determine the flow state of flow path by critical Reynolds number which is 2 200 in general.