某弹簧式灌水器流道的三维UDF动网格数值模拟

摘要

灌水器是决定微灌系统节水效果的关键部件,而优化灌水器内部结构并获得相关水力学参数成为解决灌水器优劣的主要问题,目前对灌水器的数值计算大多属于静态模拟,存在一定的局限性,为了完善新型灌水器流道内部结构,以某弹簧式灌水器为研究对象,前期进行物理模型试验测得相关参数,后期主要采用动态网格及UDF(用户自定义函数)技术,对其内部流道进行了三维动态数值模拟计算,得到了该灌水器的水头损失、上下游压差力与流量之间的关系,将数模结果与物理试验值进行对比分析后的结果表明,动态网格结合UDF的方法能够较好地模拟具有动态边界的微灌流道.%Emitter is the key part influencing the water saving effect of micro-irrigation system.The main problem of emitter is to optimize the internal structure and obtain relevant hydraulic parameters.Nowadays the numerical calculation of the emitter is mostly static simulation with some kind of boundedness.In order to improve the internal structure of the new emitter flow channel, taking one spring-loaded emitter as an object,the previous study was carried on the physical model test and relevant parameters were obtained.And then based on dynamic mesh and UDF(User-Defined Function)technology,numerical simulation for its internal flow channel was carried out,from which the flow,head loss and the relationship between the upstream and downstream pressure differential force were derived.By the contrast of numerical simulation result and physical experiment value, it is found that the combination of dynamic mesh and UDF can simulate micro-irrigation channel with dynamical boundary well.