Influence of grid resolution, parcel size and drag models on bubbling fluidized bed simulation
Influence of grid resolution, parcel size and drag models on bubbling fluidized bed simulation
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DOI：
10.1016/j.cej.2017.06.002
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发表时间：
2017-10
影响因子：
15.1
通讯作者：
Liqiang Lu;A. Konan;S. Benyahia
中科院分区：
文献类型：
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作者：
Liqiang Lu;A. Konan;S. Benyahia
本文采用不同的数值参数，如网格分辨率和颗粒尺寸，对鼓泡流化床进行了模拟。我们还研究了使用两个均匀的阻力相关性和非均匀阻力的基础上的能量最小化方法的效果。提出了一种基于连通域标记的快速、可靠的气泡检测算法。径向和轴向固体体积分数分布与实验数据和以前的模拟结果进行了比较。这些结果表明，气泡尺寸和空隙率分布的阻力模型的显着影响和数值参数的依赖性要小得多。采用考虑亚尺度结构的非均相曳力模型，可以在粗网格和大计算体积的情况下很好地捕捉鼓泡流化床内的空隙率。细化CFD网格和减小包裹尺寸可以改善模拟结果，但计算成本会大幅增加。
In this paper, a bubbling fluidized bed is simulated with different numerical parameters, such as grid resolution and parcel size. We examined also the effect of using two homogeneous drag correlations and a heterogeneous drag based on the energy minimization method. A fast and reliable bubble detection algorithm was developed based on the connected component labeling. The radial and axial solids volume fraction profiles are compared with experiment data and previous simulation results. These results show a significant influence of drag models on bubble size and voidage distributions and a much less dependence on numerical parameters. With a heterogeneous drag model that accounts for sub-scale structures, the void fraction in the bubbling fluidized bed can be well captured with coarse grid and large computation parcels. Refining the CFD grid and reducing the parcel size can improve the simulation results but with a large increase in computation cost.