# CFD Simulation of Dry Pressure Drop in a Cross-Flow Rotating Packed Bed
###### Abstract  
The cross-flow rotating packed bed (RPB) has attracted wide attention in recent years because of its advantages of large gas capacity, low pressure drop and lack of flooding limitation. However, the complex structure of the packing makes it difficult to obtain the gas flow characteristics in the cross-flow RPB by experiments. In this study, the dry pressure drop in the cross-flow RPB was investigated by computational fluid dynamics (CFD). The packing was modeled by the porous media model and the rotation of the packing was simulated by the sliding mesh model. The simulation results obtained by three turbulence models were compared with experimental results, and the RNG k-c model was found to best describe the turbulence behaviors in the cross-flow RPB. Then, the effects of gas flow rate and rotating speed on dry pressure drop in different parts of the cross-flow RPB were analyzed. The results of this study can provide important insights into the design and scale-up of cross-flow RPB.  
rotating packed bed; cross-flow; computational fluid dynamics; dry pressure drop +
Footnote †: journal: Applied Sciences  
**Cited**: [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] CFD Simulation of Dry Pressure Drop in a Cross-Flow Rotating Packed Bed.  
_Appl. Sci._**2021**, _11_, 10099. [[https://doi.org/10.3390/app112110099](https://doi.org/10.3390/app112110099)]([https://doi.org/10.3390/app112110099](https://doi.org/10.3390/app112110099))
pressure drop. Recently, [PERSON] et al. [13] used four dimensionless parameters, including swirl ratio and Renault number to depict the pressure drop. However, it should be noted that these empirical equations can hardly be applied to other cross-flow RPBs because of different empirical parameters.  
Computational fluid dynamics (CFD) provide an efficient way to investigate the hydrodynamic behaviors that are difficult to investigate experimentally, such as pressure drop, liquid flow and droplet diameter distribution in RPB [17; 18; 19; 20; 21]. [PERSON] et al. [17] investigated dry pressure drop in three RPBs using single-phase flow model and proposed a semi-empirical equation based on CFD and Ergun equation. [PERSON] et al. [20] investigated the effects of packing characteristics, such as opening porosity, distance, width and shape, on the pressure drop using a 3D single-phase flow model. [PERSON] et al. [18] investigated the effects of the gas flow rate and rotating speed on the pressure drop and found that the calculated results were lower than experimental data due to the neglect of pressure drop in inlet and outlet tube. The difference between simulated and experimental pressure drop could also be attributed to the three-dimensional effect [22] and the simplified physical model of packing [23].  
The hydrodynamic behaviors in a cross-flow RPB are so complex that they cannot be easily measured by experimental methods alone. In this circumstance, CFD can be used to clarify the important hydrodynamic characteristics without disturbing the flow field in RPB, such as drop diameter and resident time. A better understanding of pressure drop characteristics is of great importance for the design and scale-up of RPB, especially in the industrialization of desulfurization, denitrification and purification of fine particulate matter (PM2.5). In order to learn more about the spatial distribution of pressure drop, the pressure drop in different zones of the cross-flow RPB (cavity zone A, packing zone, cavity zone B and outlet zone) were analyzed in this study, and the effects of rotating speed and gas flow rate on total pressure drop, static pressure drop and kinetic pressure drop were also investigated.