滴头流道CFD分析的研究进展与问题

    Research progress in analysis of flow passage in irrigation emitters using Computational Fluid Dynamics techniques

    • 摘要: 滴头是滴灌系统重要的构成部件,其内部流道的流场直接决定了滴头性能的优劣,近几年出现的计算流体动力学(CFD)技术为准确分析滴头流场提供了一种新的途径,已成为滴头研究的热点。该文分析了滴头CFD研究现状,指出了在数值计算模型、边界条件处理方式、流动机理及采用粒子图像速度仪观测微尺度流场时存在的问题,给出了最新的计算实例,分析了影响滴头CFD模拟精度的各种因素,文中提出应按照微尺度理论建立数值分析模型,采用瞬态方法和低雷诺数湍流模式分析滴头内部流场。

       

      Abstract: Emitter is one of the key parts in micro-irrigation system. The flow-field distribution in emitter flow-passage determines the hydraulic characteristics of the emitter. It is a new way to use the computational fluid dynamics(CFD) approach to analyze exactly the flow characteristics of emitters. This paper reviews the CFD method in the research of hydraulic characteristics of emitter flow-passage, and points out the problems existing in the current numerical model, boundary condition, flow mechanism and flow behavior of micro-scale fluid-field obtained by using PIV equipment. Some numerical examples were presented. The possible factors that affect the simulation precision of emitter CFD analysis were evaluated. It is put forward that the microfluid theory should be adopted to establish the numerical model, and the unsteady method and low-Raynolds approach should be used to calibrate the model parameters of emitter flow-field.

       

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