【摘要】 迷宫滴头内部结构复杂尺寸微小,水源过滤后仍含有悬浮颗粒,研究悬浮颗粒在滴头内分布的影响因素对于滴头结构改进有重要意义。该文根据两相流理论,利用计算流体动力学软件FLUENT对迷宫滴头进行了液固两相流数值分析。采用标准k-ε湍流模型及多相流Eulerian模型,模拟得到不同入流颗粒浓度及大小时滴头内流场及颗粒浓度分布,分析了颗粒大小及入流浓度对悬浮颗粒浓度分布的影响。研究结果表明:滴头的进口、缓水区及流道拐弯区、迎水区等局部悬浮颗粒浓度增大,齿尖附近浓度接近入口浓度。除齿尖及流道背水区外,其他部位的颗粒浓度均随粒径的增大而升高;滴头内颗粒浓度分布随入流浓度的升高而升高,不同位置处浓度变化规律略有不同。更多还原

【Abstract】 The labyrinth emitter’s channel is very small and the structure is relatively complex.The irrigation water usually includes suspended sand granules even though the water has been filtrated.It is necessary to analyze the influence factors of the granules distribution in the emitter for improving emitter structure.Based on two-phase flow theory,CFD approach is introduced into the liquid-solid two-phase flow simulation in emitter in this paper.An Eulerian model of multiphase approach was used to simulate the water/sand granule flow.The velocity field and suspended granule distribution were carried out,the effects of granule size and initial volume fraction on the granules distribution were analyzed.Results show that the granule concentration increases at the inlet,store,and corner and upwind surface of labyrinth channel.Except the tooth and the downwind surface of labyrinth channel,the granule concentration increases with the increase of granule size.In general,the granule volume faction increases with the increase of inlet granule concentration,but its changing trend varies at different positions.更多还原