滴灌用水力旋流器中颗粒分离的数值模拟

针对滴灌用水力旋流器，采用高浓度混合多相流模型并结合雷诺应力模型和颗粒动力学理论对其内部颗粒体积浓度分布和分离效率进行了数值模拟。模拟首先得到了水力旋流器内不同粒径颗粒浓度分布情况和分离效果，对于小粒径颗粒主要集中在内旋流区域，分离效率较差，而大粒径颗粒集中在外旋流区域，分离效率较高；对于颗粒分离效率，混合多相流模型和欧拉多相流模型的计算结果基本一致；最后分析了旋流器进口速度和浓度变化对颗粒分离效率的影响。计算结果表明，混合多相流模型可用于水力旋流器内高浓度多相流的数值模拟，对滴灌用水力旋流器的选择和结构优化设计具有重要的指导意义。

Numerical simulation of particle separation in hydrocyclone for drip irrigation system

The mixture multiphase model combined with the RSM(reynolds stress model) and kinetic theory of granular flow for high concentration multiphase flow was used to simulate the particle volumetric concentration distribution and separative efficiency in a hydrocyclone for drip irrigation system. The distribution situation and separating effecting of different diameter particles concentrating the hydrocyclone was obtained. The small diameter particles were mainly distributed in the region of inner vertex and had higher separation efficiency. While the big diameter particles were mainly distributed in the region of outer vortex and had poor separation efficiency. The separative efficiency computed by the mixture multiphase model was in accordance with the Eula multiphase model. Then, the influence of the entrance velocity and concentration on the separative efficiency was analyzed. The simulation results showed that the mixture multiphase model was available for the numerical simulation of multi-phase flow in the hydrocyclone. The results have great importance to the choice and optimal structure designing of hydrocyclone for the drip irrigation system.