The mechanisms underlying homogeneous fluidization of Geldart A particles have long been debated. Recent experiments shed fresh insights that both a solid-like and a fluid-like state exist. Herein, 3D computational fluid dynamics-discrete element method simulations with the incorporation of interparticle van der Waals forces were performed for five typical Geldart A particles to investigate the bed structure in the homogeneous fluidization regime. Simulation results reproduce the existence of the solid-like and fluid-like states, showing that in the solid-like state, particles have enduring and strong interparticle van der Waals forces that stabilize the bed to keep the bed stationary; while in the fluid-like state, the interparticle van der Waals forces are dominated by the drag force, and particles show global circulation. Both interparticle van der Waals forces and friction are found to be necessary for the existence of the solid-like state, and increasing the former has an effect to widen the solid-like state.

中文翻译：

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Geldart A 颗粒均匀流化状态下类固体和类流体状态的 CFD-DEM 研究

Geldart A 颗粒均匀流化的机制长期以来一直存在争议。最近的实验揭示了类似固体和类似流体的状态都存在的新见解。在此，对五种典型的 Geldart A 颗粒进行了结合颗粒间范德华力的 3D 计算流体动力学-离散元方法模拟，以研究均匀流化状态下的床结构。模拟结果再现了类固态和类流体态的存在，表明在类固态下，粒子具有持久且强大的粒子间范德华力，使床层稳定，使床层保持静止；而在类流体状态下，粒子间的范德华力以曳力为主，粒子呈现全局循环。