A simple and general sub-grid drag model for gas-solid fast fluidization
A simple and general sub-grid drag model for gas-solid fast fluidization
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DOI：
10.1016/j.cej.2021.129922
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发表时间：
2021-04
影响因子：
15.1
通讯作者：
Sha Hu;Xinhua Liu
中科院分区：
文献类型：
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作者：
Sha Hu;Xinhua Liu
为了更好地利用粗网格计算流体力学（CFD）模拟预测非均质气固流动，对能量最小化多尺度（EMMS）模型进行了改进。然而，模拟中采用的阻力校正因子（Hd）通常受宏观操作条件（例如，表面气固速度，UgandGs）的影响，这就需要重建fugorgs变化时的Hd相关性。本文将EMMS子网格模型简化，用等效簇空相关取代稳定条件，使模型具有伽利略不变性，避免了在不同运行条件下hdin的重新计算。预先构建的阻力校正因子有利于在较宽的工作范围内进行气固快速流化的粗网格CFD模拟。
Great efforts have been paid to improve the Energy Minimization Multi-Scale (EMMS) model to better predict heterogeneous gas–solid flow using coarse-grid computational fluid dynamics (CFD) simulation. Nevertheless, the adopted drag correction factor (Hd) in the simulation was generally subject to macroscopic operating conditions (e.g., superficial gas and solid velocities,UgandGs), which called for rebuilding theHdcorrelation ifUgorGsvaried. In this work we simplified the EMMS sub-grid model by replacing the stability condition with an equivalent cluster voidage correlation, thus making the model possess the Galilean invariance and avoiding the recalculation ofHdin case of varying operating conditions. The pre-constructed drag correction factor can facilitate the coarse-grid CFD simulation of gas–solid fast fluidization within a broad operation range.