Abstract Filtered two-fluid formulations of gas–solid fluidized flows require closure models to deal with sub-grid filtered parameters, which have been derived from filtering over results of meso-scale highly resolved simulations with two-fluid modeling. Trusting on scale separation, the correlation of filtered parameters has been performed to meso-scale filtered data only, disregarding any macro-scale effects. In this work, the correctness of such practice is tested, and it fails. Two macro-scale parameters associated to flow topology, namely the average solid volume fraction and the average gas Reynolds number, are both considered as for their effects over relevant filtered parameters. This is done by filtering over results of highly resolved simulations, where the concerning macro-scale parameters are held constant at various levels. The current interest is directed towards dilute conditions typical of riser flows. Results show that both the concerning macro-scale parameters should be accounted for in sub-grid correlation if higher accuracy is pursued.

中文翻译：

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气固提升管流动中宏观尺度对中尺度过滤参数的影响

摘要 气固流化流的过滤二流体公式需要闭合模型来处理子网格过滤参数，这些参数是通过过滤双流体建模的中尺度高分辨率模拟结果得出的。相信尺度分离，过滤参数的相关性只对中尺度过滤数据进行，不考虑任何宏观尺度的影响。在这项工作中，测试了这种做法的正确性，但它失败了。与流动拓扑相关的两个宏观参数，即平均固体体积分数和平均气体雷诺数，都被视为它们对相关过滤参数的影响。这是通过过滤高分辨率模拟的结果来完成的，其中相关的宏观参数在各个级别保持不变。目前的兴趣是针对立管流动典型的稀释条件。结果表明，如果追求更高的精度，在子网格关联中应该考虑两个相关的宏观尺度参数。