Euler-Lagrange simulations of gas-solid flows in unbounded domains have been performed to study sub-grid modeling of the filtered drag force for non-cohesive and cohesive particles. The filtered drag forces under various microstructures and flow conditions were analyzed in terms of various sub-grid quantities: the sub-grid drift velocity, which stems from the sub-grid correlation between the local fluid velocity and the local particle volume fraction, and the scalar variance of solid volume fraction, which is a measure to identify the degree of local inhomogeneity of volume fraction within a filter volume. The results show that the drift velocity and the scalar variance exert systematic effects on the filtered drag force. Effects of particle and domain sizes, gravitational accelerations, and mass loadings on the filtered drag are also studied, and it is shown that these effects can be captured by both sub-grid quantities. Additionally, the effect of cohesion force through the van der Waals interaction on ...

中文翻译：

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面向非粘性和粘性颗粒气流的过滤阻力模型

已经进行了无界域中气固流的欧拉-拉格朗日模拟，以研究非粘性和粘性粒子的过滤阻力的子网格建模。不同微观结构和流动条件下的过滤阻力从不同的子网格量进行分析：子网格漂移速度，它源于局部流体速度和局部粒子体积分数之间的子网格相关性，以及固体体积分数的标量方差，这是识别过滤器体积内体积分数局部不均匀程度的度量。结果表明，漂移速度和标量方差对过滤阻力产生系统影响。还研究了粒子和域尺寸、重力加速度和质量载荷对过滤阻力的影响，并且表明这些影响可以被两个子网格量捕获。此外，内聚力通过范德瓦尔斯相互作用对...的影响