Shamshery Pulkit, Wang Ruo-Qian, Tran Davis V, Winter V Amos G
Global Engineering and Research Laboratory, Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America.
PLoS One. 2017 Apr 6;12(4):e0175241. doi: 10.1371/journal.pone.0175241. eCollection 2017.
Drip irrigation is a means of distributing the exact amount of water a plant needs by dripping water directly onto the root zone. It can produce up to 90% more crops than rain-fed irrigation, and reduce water consumption by 70% compared to conventional flood irrigation. Drip irrigation may enable millions of poor farmers to rise out of poverty by growing more and higher value crops, while not contributing to overconsumption of water. Achieving this impact will require broadening the engineering knowledge required to design new, low-cost, low-power drip irrigation technology, particularly for poor, off-grid communities in developing countries. For more than 50 years, pressure compensating (PC) drip emitters-which can maintain a constant flow rate under variations in pressure, to ensure uniform water distribution on a field-have been designed and optimized empirically. This study presents a parametric model that describes the fluid and solid mechanics that govern the behavior of a common PC emitter architecture, which uses a flexible diaphragm to limit flow. The model was validated by testing nine prototypes with geometric variations, all of which matched predicted performance to within R2 = 0.85. This parametric model will enable irrigation engineers to design new drip emitters with attributes that improve performance and lower cost, which will promote the use of drip irrigation throughout the world.
滴灌是一种通过将水直接滴到植物根区来精确供应植物所需水量的灌溉方式。与靠雨水灌溉相比，它能使作物产量提高多达90%，与传统的漫灌相比，可减少70%的用水量。滴灌或许能让数百万贫困农民通过种植更多高价值作物摆脱贫困，同时又不会造成水资源的过度消耗。要实现这一影响，需要拓宽设计新型低成本、低功率滴灌技术所需的工程知识，特别是针对发展中国家贫困的离网社区。五十多年来，压力补偿（PC）滴头——能在压力变化时保持恒定流速以确保田间水分布均匀——一直是通过经验设计和优化的。本研究提出了一个参数模型，该模型描述了控制一种常见PC滴头结构行为的流体力学和固体力学，这种滴头采用柔性隔膜来限制水流。通过测试九个具有几何变化的原型对该模型进行了验证，所有原型的预测性能与实际性能的匹配度均在R2 = 0.85以内。这种参数模型将使灌溉工程师能够设计出具有改进性能和降低成本特性的新型滴头，这将推动滴灌在全球的应用。
