Why the two-fluid model fails to predict the bed expansion characteristics of Geldart A particles in gas-fluidized beds: A tentative answer
Why the two-fluid model fails to predict the bed expansion characteristics of Geldart A particles in gas-fluidized beds: A tentative answer
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DOI：
10.1016/j.ces.2008.09.028
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发表时间：
2009-02
影响因子：
4.7
通讯作者：
Junwu Wang;van der M.A. Hoef;J. Kuipers
中科院分区：
文献类型：
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作者：
Junwu Wang;van der M.A. Hoef;J. Kuipers
众所周知，双流体模型（TFM）可以成功地预测Geldart B和D颗粒的流体力学。然而，到目前为止，TFM未能准确描述GeldartA颗粒在鼓泡气体流化床内的流体动力学：研究人员报告说，床膨胀被高估了70%。在这项工作中，我们表明，第一次，TFM可以预测正确的床膨胀，没有任何人为的修改，提供了一个足够细的网格尺寸和小的时间步长。这表明，先前报道的TFM的失败主要是由于缺乏尺度分辨率，并且从建模的角度来看，Geldart A颗粒与Geldart B和D颗粒之间没有根本差异。
It is well known that two-fluid models (TFMs) can successfully predict the hydrodynamics of Geldart B and D particles. However, up to now, TFM have failed to accurately describe the hydrodynamics of Geldart A particles inside bubbling gas-fluidized beds: Researchers have reported that bed expansions are over-predicted by as much as 70%. In this work we show—for the first time—that TFM can predict the correct bed expansion, without any artificial modifications, provided that a sufficiently fine grid size and small time step is used. This suggests that the previously reported failure of TFM is mainly due to the lack of scale resolution, and that from a modeling point of view there is no fundamental difference between Geldart A particles and Geldart B and D particles.