Abstract In a fluidized bed system, mean trajectories of fuel particles within the bed of fluidized inert particles are governed by the associated drag forces and characterize hydrodynamic, chemical and thermal processes taken place in the system. A large particle size ratio between the bed material and the fuel particles affects the hydrodynamics of gas-solid multiphase flows via influencing the drag forces between solid phases. The present work focuses on the analysis of forces between the two solid phases with large size ratios using the Lagrangian simulations of discrete element method (DEM). The results are spatially averaged over variable control volume size for comparison to the continuum interphase momentum transfer model. Using our DEM simulation results, a correction factor of drag force is presented versus the size of averaging control volume usable in continuum models. In addition, the role of inhomogeneity of particles distribution within the averaging box is discussed.

中文翻译：

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就大粒径比混合物的空间平均而言，固体-固体动量传递速率的连续体公式的偏差

摘要 在流化床系统中，流化惰性颗粒床内燃料颗粒的平均轨迹由相关的阻力控制，并表征系统中发生的流体动力学、化学和热过程。床层材料和燃料颗粒之间的大粒径比通过影响固相之间的拖曳力来影响气固多相流的流体动力学。目前的工作重点是使用离散元法 (DEM) 的拉格朗日模拟分析具有大尺寸比的两个固相之间的力。结果在可变控制体积大小上进行空间平均，以与连续相间动量传递模型进行比较。使用我们的 DEM 模拟结果，阻力的修正系数相对于连续模型中可用的平均控制体积的大小。此外，还讨论了平均框内粒子分布不均匀的作用。