| 摘要: |
| 【目的】探究旋流式固液两相流泵内流动特征。【方法】基于CFD-DEM（Computational Fluid Dynamics-Discrete Element Method）耦合模型，选用油菜籽颗粒，在不同流量工况和颗粒体积分数下对旋流泵固液两相流场进行数值模拟和试验研究，研究旋流式固液两相流泵的内部流动规律及颗粒分布特征。【结果】小流量工况下循环流漩涡特征较明显，进口旋转回流长度较长，对进口来流扰动较大，随着流量增大，循环流影响范围减小；泵内颗粒受到贯通流和循环流的共同作用。管壁中心颗粒受贯通流的影响较大，颗粒穿过无叶腔直接进入叶轮，而靠近管壁的颗粒受循环流的影响较大；叶轮内沿着轴向3个截面处颗粒分布有着较为明显的差异，从叶轮前端面到后盖板，颗粒数量逐渐增多；蜗室内存在一对旋转方向相反的漩涡，在第Ⅴ断面之后前侧涡束逐渐消散，后侧涡束一直旋转至第Ⅷ断面处；在贯通流和循环流的作用下，油菜籽颗粒被旋转回流沿着管壁面带入到进口区域。【结论】循环流的存在导致旋流泵效率较低，但在输送颗粒时循环流起到较大的作用，使得泵输送性能较强；模型泵数值模拟与试验结果基本一致，验证了模拟的可靠性。 |
| 关键词: 旋流式固液两相流泵；CFD-DEM耦合计算；循环流；高速摄影；进口旋转回流 |
| DOI：10.13522/j.cnki.ggps.2022124 |
| 分类号:TH314 |
| 基金项目:国家自然科学(51909108),泰山产业领军人才工程专项经费资助(tscy20200225)。 |
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| Numerical simulation and experimental study of vortex solid-liquid two-phase flow pump based on CFD-DEM |
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Zhaoting, gaoxiongfa
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Jiangsu University
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| Abstract: |
| 【Objective】To explore the flow characteristics in vortex solid-liquid two-phase flow pump.【Method】Based on the CFD-DEM (Computational Fluid Dynamics-Discrete Element Method) coupled model, rapeseed particles were selected to conduct numerical simulations and solid-liquid two-phase flow experiments on the solid-liquid two-phase flow field of a vortex pump under different flow conditions and particle concentrations, to study the internal flow law and particle distribution characteristics of the vortex solid-liquid two-phase flow pump. 【Results】The study found that: under the condition of low flow rate, the vortex characteristics of the circulating flow in the lateral cavity are more obvious, the length of the inlet rotation and return flow is longer, and the disturbance to the inlet flow is larger. As the flow rate increases, the radius of the circulating flow decreases, the range of influence is reduced. The particles in the pump are subject to the combined action of the through flow and the circulating flow. The particles in the center of the tube wall are greatly affected by the through flow, and the particles pass through the lateral cavity and directly enter the impeller. The particles near the pipe wall are greatly affected by the circulating flow. The distribution of particles in the three sections along the axial direction in the impeller has obvious differences, and the number of particles gradually increases from the front end of the impeller to the rear cover. For the vortices with opposite rotation directions, the front vortex beam gradually dissipates after the V section, and the rear vortex beam rotates all the way to the eighth section. Under the action of the through flow and the circulating flow, the rapeseed particles are brought into the inlet area along the pipe wall by the rotating backflow. 【Conclusion】The existence of circulating flow leads to the low efficiency of vortex pump, but the circulating flow plays a great role in conveying particles, which makes the pump have strong conveying performance; the numerical simulation of the model pump is basically consistent with the experimental results, which verifies the reliability of the simulation. |
| Key words: Vortex solid-liquid two-phase flow pump, CFD-DEM coupling calculation, circulating flow, high-speed photograph, inlet rotating backflow |
