Through particle‐resolved direct numerical simulations of flows past random arrays of oblate ellipsoids at low Reynolds numbers, this work demonstrates how the drag force on oblate ellipsoids depends on the Hermans orientation factor S, the mean crosswise sphericity φ_⊥, the aspect ratio AR, and the solid volume fraction c. Wide ranges of S, AR, and c are considered and they are in the intervals (−0.5, 1), (0.2, 0.8), and (0.1, 0.4), respectively. This study extends the work on prolate ellipsoids by Li et al (AIChE Journal, 2019, 65, e16621). Based on the simulation results, two models are respectively developed using S and φ_⊥as the independent orientation factor. The model based on S could give accurate prediction of the drag force and the lateral force exerted on arrays of particles. The model based on φ_⊥ is able to use one generalized drag correlation for both oblate and prolate ellipsoids.

中文翻译：

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低雷诺数流动中扁球形椭圆体随机排列中颗粒取向对阻力的影响

通过过去的低雷诺数扁椭球的随机阵列流动的颗粒分辨直接数值模拟中，这项工作表明上扁椭球的拖曳力是如何依赖于赫尔曼取向因子小号，平均横向球形度φ _⊥，纵横比AR，和固体体积分数c。考虑到较大的S，AR和c范围，它们分别在（-0.5，1），（0.2，0.8）和（0.1，0.4）区间中。这项研究扩展了Li等人在长椭球体上的研究（AIChE Journal，2019，65，e16621）。根据仿真结果，分别使用S开发了两个模型和φ _⊥作为独立定位的因素。基于S的模型可以准确预测施加在粒子阵列上的阻力和横向力。基于该模型φ _⊥能够使用一个通用的阻力相关的两个扁圆和扁长的椭圆体。