【作者】 徐文礼；

【导师】 李治勤；

【作者基本信息】 太原理工大学 ， 水力学及河流动力学， 2008， 硕士

【摘要】 我国是一个干旱缺水严重的国家,水资源危机严重地威胁了我国社会的可持续发展,它不仅导致生态环境的恶化,而且威胁粮食安全和国民经济发展,因此节水灌溉日俱紧迫且必要。在诸如管灌、喷灌等诸多的节水灌溉技术中,滴灌具有省水、节能、增产、灌水均匀、对土壤和地形的适应性强等优点,但它也有缺点,如易于堵塞、限制根系发展等,其中最主要的缺点是滴灌灌水器的堵塞问题。滴灌灌水器的堵塞是目前滴灌系统难以解决的瓶颈问题,灌水器的堵塞与灌水器中水流流动特性及泥沙颗粒在灌水器内的运动特性有关,因此,本文利用Fluent软件对迷宫式滴灌带灌水器中水流流动特性进行数值模拟分析,同时利用两相流理论对迷宫式滴灌带灌水器中泥沙颗粒的运动特性进行了数值模拟分析。分析结果表明:1)灌水器迷宫流道内存在“低速区”,当灌水器中的泥沙颗粒运动至此“低速区”内时很容易在该处沉积,从而造成迷宫灌水器的堵塞;2)泥沙颗粒粒径是迷宫式灌水器堵塞的主要因素,对迷宫灌水器的堵塞起着决定性的作用;3)颗粒与壁面碰撞系数的大小即灌水器制作材料的特性对灌水器的堵塞有一定的影响,如果灌水器制作材料的恢复系数太小灌水器就很容易产生堵塞;4)浑水含沙量的大小在一定的范围内对迷宫式灌水器的堵塞影响较小;5)迷宫灌水器中水流流速对灌水器的堵塞产生的影响有待进一步研究。更多还原

【Abstract】 China is an arid country thirsty of water. Water resources crisis has influenced the continuous development of our country seriously. It not only leads to the ecological environment worsening, but also influences the food security and national economy development. Therefore, it is urgent and necessary to carry out water-saving irrigation. Drip irrigation has the advantages of Provincial-Water, Energy-Saving, Production-Increasing, Irrigation Uniformity and the adaptability to the soil and terrain compared with other water-saving irrigation techniques, such as the tube fills, the spray irrigation and so on. But the drip Irrigation also has many drawbacks, such as easy to clog, restricting root development etc. The most important of which is easy to plug-drip irrigation.The clogging of drip irrigation emitter is a bottleneck problem that drips irrigation system faced with currently. We comprehensively use various physical-chemical methods to deal with the clogging. But the drip irrigation emitter still has the clogging in some degree. The clogging of drip irrigation is related with the water flow characteristics in the drip irrigation emitter and the movement characteristics of sand particles in the water flow in the drip irrigation emitter. Therefore, we utilized software FLUENT on the numerical simulation of the clogging features inside the labyrinth emitter, meanwhile, two-phase flow theories were applied to study the state of flow and particle motion within it.The results are as follows :1) There exist low velocity regions in the body of labyrinth channel. It is easy to deposit and leads to the clogging of drip irrigation emitter When sediment particle in the labyrinth emitter flow down the low velocity regions.2) The sediment particle diameter is the primary factor and plays a definitive role in the clogging of the drip irrigation emitter.3) How the speed of water flow influence the clogging of drip irrigation emitter needs to study further.4) Particle collision with the wall coefficient has some effect on the clogging of the drip irrigation emitter. If the manufacture material’s recovery coefficient of emitter is too small ,then the drip irrigation emitter is easy to be clogged 5) The muddy water concentration within a certain scope influence the clogging drip irrigation emitter is very little.更多还原