Pore-scale simulation of flow and turbulence characteristics in three-dimensional randomly packed beds
Pore-scale simulation of flow and turbulence characteristics in three-dimensional randomly packed beds
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DOI：
10.1016/j.powtec.2018.06.013
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发表时间：
2018-10
影响因子：
5.2
通讯作者：
Jiang Linsong;L. Hongsheng;Suo Shaoyi;Xie Mao-zhao;Wu Dan;Bai Minli
中科院分区：
文献类型：
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作者：
Jiang Linsong;L. Hongsheng;Suo Shaoyi;Xie Mao-zhao;Wu Dan;Bai Minli
对实际填料床内不同操作条件下的流体流动和湍流特性进行了孔尺度的数值模拟。采用离散元软件LIGGSTUDIO（LAMMPS Improved for General Granular and Granular Heat Transfer Simulations）对随机填充床的真实的几何结构进行了模拟。数值模型与实验数据进行了验证。预测结果与实测结果吻合较好。研究了气速、颗粒粒径等参数对反应的影响。对平均参数的宏观分析结果表明，在填充床内，平均孔隙率和流动参数均呈波动变化。随着颗粒半径的增加，平均速度和压力的波动增加。局部细节分析结果表明，填充床孔隙中存在复杂的湍流涡流结构。大尺度涡主要分布在主通道入口和球壁附近，高强度涡主要分布在球壁上方和主通道右侧。
Fluid flow and turbulence characteristics were numerically simulated at the pore scale in actual packed beds under different operating conditions. Real geometrical structures of randomly packed beds were modeled using the discrete element software LIGGGHTS (LAMMPS Improved for General Granular and Granular Heat Transfer Simulations). The numerical model was validated against experimental data. Good agreements were achieved between the predicted results and measurements. The influences of different parameters, such as the gas velocity and particle, size were studied and discussed in detail. The results of a macroscopic analysis of the mean parameters show that inside the packed beds, both the mean porosity and flow parameters had fluctuate variations. As the pellet radius increased, the fluctuations in the mean velocity and pressure increased. The results of a local detail analysis demonstrate that complicated turbulent eddy structures exist in the pores of the packed beds. Eddies with large sizes were primarily distributed at the entrance of the main channel and near the spherical wall, and eddies with high intensities were mainly distributed near the above spherical wall and on the right side of the main channel.