Computational fluid dynamics simulations of fluid flow through the packed beds: A study of contact point treatments

This study presents a comprehensive computational investigation of the effects of inter-particle contact point treatments on pressure drop predictions in fluid flow through fixed beds. Using Reynolds-averaged Navier–Stokes simulations, the impact of particle diameter adjustments ( ± 0.02% to ± 10%) on flow characteristics, mesh quality, and numerical accuracy was systematically evaluated. A comparison of gap and overlap methods for a packed bed filled with spherical particles of diameter D p demonstrates that minor geometric modifications (up to 1% scaling) significantly alter pressure drop in the packed bed, with optimal fidelity achieved at a slight overlap ( Δ D p ≈ 0 . 5 % ). Two turbulence models ( k - ω Shear Stress Transport (SST) and k - k l - ω ) are assessed, revealing model-dependent sensitivities to contact treatments: the k - k l - ω model excels for small gaps ( − 0 . 2 % ≤ Δ D p ≤ 0 % ), while SST performs better for large overlaps ( + 0 . 2 % ≤ Δ D p ≤ + 2 % ). A square domain that was 260 mm long and had a cross-section of 20 × 20 mm was packed with spherical particles in 2 × 2 stacked layers. The particle size ranged from 9.9 to 10.1 mm. Derived inlet velocity ranged from 3.7 to 9.5 m/s. Validation against experimental data shows a mean absolute error of < 4 . 5 % for pressure drop predictions. The results provide quantitative guidelines for selecting contact point treatments in computational fluid dynamics simulations, balancing accuracy with computational feasibility. This work advances the modeling of packed beds by linking microscale geometric adjustments to macroscopic flow predictions, offering practical insights for reactor design and optimization. • Optimal +0.5% overlap minimizes pressure drop error (<6% MAE). • Turbulence model choice critical: k-kl- ω for gaps, SST for overlaps. • Mesh quality degrades near contact points (−2% ≤ Δ Dp ≤ +2%). • Overlaps outperform gaps in flow stability ( Δ Dp ≤ +1%). • Quantified Δ Dp effects on packed bed.