Brazilian Journal of Chemical Engineering ( IF 1.5 ) Pub Date : 2021-07-21 , DOI: 10.1007/s43153-021-00134-1 João P. F. Campos 1 , Gabriela C. Lopes 1, 2 , Karla R. B. Melo 2
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Abstract
Numerical simulations using CFD-DEM (Computational Fluid Dynamics—Discrete Elements Method) are used to investigate the hydrodynamic behavior of the phases in solid–liquid fluidized beds. However, some challenges are posed to the prediction of energy dissipation and bed expansion on these systems—little knowledge on the collision effects on the solid phase and the high computational cost of assessing the dissipative effects of the lubrication force resulting from the liquid phase. In this context, the present study assessed the collision effects based on the coefficient of restitution, the main parameter of contact between the particles, and the influence of the lubrication force on the dynamics of a fluidized bed. For this, a lubrication force model was implemented in an open-source software CFDEM®project. The model was tested for collisions with fluids of different viscosities and showed good agreement with experimental data. Furthermore, the model was applied to the simulation of a fluidized bed using a high viscosity liquid and dense particles and the results indicated that the lubrication force had a significant impact on the bed dynamics, influencing the fraction of voids, porosity and particle velocity.
Graphic abstract
中文翻译：
润滑力模型在 CFD-DEM 模拟中的实施、验证和应用
摘要
使用 CFD-DEM（计算流体动力学 - 离散元方法）的数值模拟用于研究固液流化床中各相的流体动力学行为。然而，对这些系统的能量耗散和床膨胀的预测提出了一些挑战——对固相的碰撞影响知之甚少，以及评估由液相产生的润滑力的耗散影响的高计算成本。在这种情况下，本研究根据恢复系数、颗粒之间接触的主要参数以及润滑力对流化床动力学的影响来评估碰撞效应。为此，在开源软件 CFDEM® 项目中实施了润滑力模型。该模型在与不同粘度的流体碰撞时进行了测试，并显示出与实验数据的良好一致性。此外，将该模型应用于使用高粘度液体和致密颗粒的流化床模拟，结果表明润滑力对床的动力学有显着影响，影响空隙率、孔隙率和颗粒速度。
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