We investigate the average drag, lift, and torque on static assemblies of capsule‐like particles of aspect ratio 4. The performed simulations are from Stokes flow to high Reynolds numbers (0.1 ≤ Re ≤ 1,000) at different solids volume fraction (0.1 ≤ ɛ_s ≤ 0.5). Individual particle forces as a function of the incident angle ϕ with respect to the average flow are scattered. However, the average particle force as a function of ϕ is found to be independent of mutual particle orientations for all but the highest volume fractions. On average, a sine‐squared scaling of drag and sine‐cosine scaling of lift holds for static multiparticle systems of elongated particles. For a packed bed, our findings can be utilized to compute the pressure drop with knowledge of the particle‐orientation distribution, and the average particle drag at ϕ = 0° and 90°. We propose closures for average forces to be used in Euler–Lagrange simulations of particles of aspect ratio 4.

中文翻译：

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轴对称细长粒子单分散组件上的流体动力：取向和空隙效应

我们研究了纵横比为 4 的胶囊状颗粒静态组件的平均阻力、升力和扭矩。执行的模拟是从斯托克斯流到不同固体体积分数 (0.1 ≤ ɛ ) 的高雷诺数 (0.1 ≤ Re ≤ 1,000)  _s  ≤ 0.5)。作为相对于平均流的入射角φ的函数的单个粒子力是分散的。然而，作为φ的函数的平均粒子力被发现与除了最高体积分数之外的所有粒子的相互取向无关。平均而言，阻力的正弦平方标度和升力的正余弦标度适用于细长粒子的静态多粒子系统。对于填充床，我们的研究结果可用于计算压降，了解粒子取向分布，以及φ = 0° 和 90° 时的平均粒子阻力。我们建议在长宽比为 4 的粒子的 Euler-Lagrange 模拟中使用平均力的闭包。