A novel model of pressure drop for airflow penetrating randomly packed cylindrical particles

Pressure drop is the key factor related to performance and energy consumption of fixed bed. However, the packing of cylindrical particles produces anisotropic gaps and an extremely complex airflow field and makes the formation mechanism of flow resistance undefined. This study conducted a comprehensive investigation on how such factors as the void fraction, diameter, and aspect ratio of cylinders on the flow resistance, in terms of experimental and numerical methods. With the DEM-CFD simulation, the laminar and transitional flow pattern was acquired, and the critical Reynolds number was determined. The expression of void fraction in the inertia term of the original Ergun equation was confirmed not applicable to cylindrical particles, which was proved to be the reason why previous predictions cannot accurately give the flow resistance of packed cylindrical particles. Finally, a new prediction model for the pressure drop of airflow penetrating the packed cylindrical particles was developed.