旋流泵在输送大尺度颗粒时固液、固固及固壁间的交互作用，导致输送含大尺度颗粒时颗粒的复杂流动和流道堵塞，是固液混输工农业领域急需解决的难题之一，研究大尺度颗粒的流动机理是解决该问题的基础研究。本项目以弯管和旋流泵模型为研究对象，采用数值计算、高速摄影、3D-PIV等模拟与实验手段展开研究。1）基于CFD-DEM耦合算法计算大尺度颗粒在弯管内的流动特性，并与实验对比验证，找出适合计算大尺度颗粒运动的湍流模型和算法。2）基于多向耦合计算方法，探明大尺寸颗粒在无叶腔与叶轮流道内的复杂流动轨迹和流动特性，掌握泵腔内的压力场、涡量场、涡耗散、湍动能及其生成等湍流特性，揭示固液间多向耦合特性与流动机理的关联性。3）基于可视化实验，分析固体颗粒的周期性演化特性，以及大尺度颗粒在不同相位时的流动轨迹差异性，阐明固相-液相、固相-固相，固相-壁面间交互作用诱导旋流泵堵塞的原因，揭示大尺度颗粒复杂的输送机理。

One of the challenges in solid-liquid mixing pumping of industry and agriculture is the intricate turbulence characteristic inside the bladeless chamber and flow channel when vortex pump is employed to pump large-scale particles. Interaction of fluid-particle、particle-particle and particle-wall are normally responsible for this flow behavior and can be solved by investigating the flow mechanism of the large-scale particles. In this project, elbow pipe and vortex pump are studied by means of numerical simulation, high-speed photography and 3D-PIV. 1) Based on the CFD-DEM coupling algorithm, calculating and verifying the flow characteristics of large-scale particles in curved tubes by simulations and experiments, finding the turbulence models and algorithms suitable for calculating large-scale particle motion. 2) Based on the multi-directional coupling method, exploring the three-dimensional motion trail and flow characteristic of large-scale particles in the bladeless chamber and flow channel, understanding the characteristics of pressure, vorticity, eddy dissipation and turbulence kinetic energy, revealing the correlation between solid-liquid multi-directional coupling characteristic and flow mechanism. 3) Based on the visualization experiment, analyzing the periodical evolution feature of particles and discrepancy of flow track in different phases, explaining the fluctuation characteristics of pressure field induced by interactions of solid-liquid, solid-solid and solid-wall, revealing the complicated pumping mechanism of large-scale particles.