Two different methods for closure modeling of the unresolved terms appearing in the filtered two-fluid model are discussed and compared. The spatially averaged two-fluid model is based on generalizing the concepts of large eddy simulation to gas-particle flows. In the approximate deconvolution method-two-fluid model approach, the unresolved terms are modeled by an approximate deconvolution method, where an approximation of the unfiltered solution is obtained by repeated filtering. Finally, these models are applied to a lab-scale and a pilot-scale fluidized bed. Both approaches yield fairly good agreement with a highly resolved reference simulation as well as with experimental data. Additionally, both methods deliver reasonable grid-independent solutions up to a grid resolution of 2 cm in the case of Geldart type A particles.

中文翻译：

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流化气颗粒悬浮液空间平均模型的验证和验证

讨论和比较了两种不同的方法，用于对过滤后的双流体模型中出现的未解析项进行闭合建模。空间平均二流体模型基于将大涡模拟的概念推广到气体-颗粒流。在近似解卷积方法-双流体模型方法中，未解析项通过近似解卷积方法建模，其中通过重复滤波获得未滤波解的近似值。最后，将这些模型应用于实验室规模和中试规模的流化床。两种方法都与高度解析的参考模拟以及实验数据产生了相当好的一致性。此外，在 Geldart A 型粒子的情况下，这两种方法都提供了合理的网格独立解决方案，网格分辨率高达 2 cm。