Abstract The prediction of the pressure drop of packed beds requires an accurate estimation of the packed-bed porosity as its error propagation multiplies the occurring errors by a factor of about four. For a better understanding of the packed bed's local porosity characteristics, a comprehensive x-ray tomography study was performed investigating and correlating the void structure of packed beds made of smooth, mono-sized spheres in cylindrical confining walls having tube-to-particle diameter ratios λ = 3.0 to 9.0 reinforced by numerically generated packed beds of λ = 1.1 to 9.0. An in-depth analysis of the obtained oscillating void profiles is performed, discussing the locations and heights of porosity extrema. Most importantly, a significant and in parts surprising extrema formation in the tube's center is described, especially present for λ

中文翻译：

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球体随机填充床中空隙结构的实验和数值分析

摘要 填充床压降的预测需要对填充床孔隙度进行准确估计，因为其误差传播将发生的误差乘以大约四倍。为了更好地了解填充床的局部孔隙率特征，进行了全面的 X 射线断层扫描研究，以调查和关联由光滑、单一尺寸的球体在具有管与颗粒直径比的圆柱形围壁中制成的填充床的空隙结构λ = 3.0 至 9.0 由 λ = 1.1 至 9.0 的数值生成填充床增强。对获得的振荡空隙轮廓进行了深入分析，讨论了孔隙度极值的位置和高度。最重要的是，描述了管中心的显着且部分令人惊讶的极值形成，