Particle-resolved CFD simulation of fixed bed pressure drop at moderate to high Reynolds number.

Particle-resolved computational fluid dynamics simulations of flow and pressure drop in fixed beds of spheres give poor accuracy at higher Reynolds number (Re) under turbulent conditions. The influence of meshing is investigated for two cases, a face centered cubic packing with no wall effects, and a narrow bed of tube-to-particle diameter ratio three with strong wall effects. Local approaches to meshing at contact points were compared, using both surface flattening (caps) and bridging between spheres. Accurate results for pressure drop at moderate to high Re > 1000 required computationally expensive fine uniform meshes, however at highest Re pressure drop appeared to be low. The use of boundary adaption improved results with less expensive meshes. The aspect ratio of surface prisms and the sizes of the bridges used at contact points had strong effects. Velocity profiles were much less sensitive to the mesh refinement and could be obtained at reasonable cost. [Display omitted] • Systematic body-fitted mesh development for pressure drop in beds of spheres. • Fine uniform meshes give accurate pressure drop, are impractical for full beds. • Bridges used for contact point treatment should be relatively small. • If prism cells are used on surfaces their aspect ratio should be below five. • Accurate pressure drop computations need finer meshes than velocity profiles. [ABSTRACT FROM AUTHOR]