【摘要】 为了研究低压滴灌毛管压力变化规律,本试验对Φ16孔口式滴灌管在不同的入口水头(0.5~2.0 m)和不同管道铺设长度(20、406、0 m)状态下沿程压力进行了测定。结果表明,运用规范中给定的计算结果与试验测试结果进行比较,相差较大,规范中的沿程水头损失计算公式不能满足孔口式滴灌管在低压条件下的损失。在管道长度为20 m和40 m,工作水头为0.5 m时,试验测试水头损失约为规范公式计算结果的30倍多,但随着入口工作水头的增加,两者之间的比值有趋于减少的趋势。同时,Excel软件的拟合表明,低压滴灌孔口式出流沿程压力分布符合以入口水头为基本参数的指数函数关系,并给定了相关参数的经验取值范围,其中水头损失修正系数k=1.004~1.0183;指数修正系数θ的取值为0.004到0.021。更多还原

【Abstract】 In order to study the variation law of low pressure trickle irrigation laterals,under 0.5～2.0 m work head and different laterals with the length of 20,40 and 60 m,orifice outlet drip irrigation laterals’ linear pressure with a diameter of Φ16 are measured.The results show that there are great differences between calculation results calculated by formula according to the specifications and measured value.Linear head loss calculation formula in specifications can not meet the orifice outlet drip irrigation laterals’ head losses calculation under low pressure condition.Head losses of measured values is bigger than that calculated by formula for more than 30 times under condition of 0.5 m work head and lateral with the length of 20 and 40 m,and the ratio of them has the tendency of reducing with the increasing of inlet work head.After fitting by excel,it shows that pressure distribution carried with laterals conforms to an exponent function relation which considers inlet pressure as a basic parameter,and gives the experimental value range of related parameters as: head losses correction coefficient k=1.004～1.0183 and exponent correction coefficient θ=0.004～0.021.更多还原