Pressure drop is crucial to the design and operation of packed beds, necessitating a thorough knowledge of flow behavior for precise pumping power estimation. Despite extensive research on random packings, the hydrodynamic performance of structured packed beds remains insufficiently understood. In the present work, the pressure drop characteristics in structured packed beds with rhombohedral and orthorhombic configurations is explored by employing the computational fluid dynamics (CFD) method. It can be found that the pressure drop increases with superficial velocity, while the friction factor generally decreases with the modified Reynolds number. Additionally, both pressure drop and friction factor in the rhombohedral series decrease with increasing spacing between adjacent particles. In the orthorhombic series, however, these two quantities initially decline, then rise, and finally decline again as the spacing progressively increases. The influence of porosity on pressure drop is rather complex: the maximum values occur at the minimum porosity, whereas their minimum values are observed at intermediate porosity rather than at the maximum porosity. At the same porosity, rhombohedral packed beds exhibit lower flow resistance than orthorhombic beds. A comparison between the simulation results and empirical correlations indicates that classical models developed for random configurations are unsuitable for structured ones. Further in‑depth investigations are therefore warranted to elucidate the effects of packing structure and to establish validated correlations for structured packed beds.
 

structured packed beds,CFD,pressure drop,porosity,empirical corelation