Impact of flow direction on the isothermal pressure drop through a packed bed of crushed rock – A DEM-CFD approach

Abstract

Pressure drop plays a crucial role in the design of a packed bed of crushed rock, necessitating a deep understanding of flow behaviour for precise determination of pumping power. This study employs ellipsoidal particles to represent crushed rock, matching the volume and aspect ratio of the sampled rocks. A discrete element model was employed to generate packed beds of ellipsoidal particles, while computational fluid dynamics simulated the flow through the voids in different directions. The model's findings were validated against experimental results from both ellipsoidal particles and crushed rocks. While the ellipsoids effectively capture general flow trends, they underestimate pressure drop through crushed rocks by 5% horizontally and overestimate it by 20% vertically. Consequently, the study proposed a correlation to predict pressure drop in a packed bed using the porous media approach, expressing inertial resistance as a tensor to capture flow direction effects. • DEM-CFD shows flow impact on pressure drop in rock beds, enhancing energy storage design. • Using ellipsoids to represent rock particles enhances flow prediction, benefiting thermal energy systems. • Ellipsoids capture flow trends but misestimate rock pressure drop by 5% horizontally, 20% vertically. • New equation predicts pressure drop in rock beds, optimizing thermal energy storage design.