插入式滴灌管局部阻力相邻影响研究

Local Resistance Interaction in Trickle Laterals Equipped with Integrated On-line Emitters

为研究插入式滴头局部阻力间的相互影响，以φ16插入式滴灌管为研究对象，设置6种滴头间距进行灌水试验，同时采用CFD模拟并分析验证。在此基础上对φ20滴灌管进行了模拟研究。结果表明：滴头局部阻力相邻影响系数模拟结果与试验结果基本吻合；滴头局部阻力相邻影响系数随滴头间距的减小而减小；滴头前后扰动范围和流速分布的变化是滴头局部阻力产生相邻影响的主要原因；滴灌设计中，当滴头间距小于0．5m时，应考虑滴头局部阻力间的相邻影响，相邻影响系数取值范围为0．9—1．0。

In drip irrigation design, calculation method of emitter local resistance coefficient is different with different arrangements and the local resistance interaction is existed under some conditions. Local resistance interaction of emitters was appeared when the emitter spacing was less than a critical value, at this time, the emitter local resistance was different from local resistance in independent emitters. Local resistance coefficient would be calculated separately with different methods and different emitter spacings. Based on this, water filling tests of φ16 drip pipe with six kinds of emitters spacings were conducted to investigdte the interaction of local resistance in trickle laterals of on-line emitters. Meanwhile, the CFD software was applied on numerical simulation and verification. On this basis, φ20 drip pipeswere simulated. The results showed that the simulatedvalues were in agreement with the experimental values for local resistance interactive coefficient of emitters. The local resistance interactive coefficient reduced with the decreasing emitters spacing. The changes of disturbance range and velocity distribution near the emitters were the main reasons for local resistance interaction in trickle laterals. Local resistance interaction of emitters should be taken into account when the emitter spacing was less than 0.5 m. In this case, the values of interactive coefficient were varied from 0.9 to 1.0.