Two-Phase flow characterization of a rotating packed bed through CFD simulation in OpenFOAM

Abstract

• Characterize a rotating packed bed by a new numerical model developed in OpenFOAM. • Equipped the new model with new features, including relative resistance formulation. • The verified and validated OpenFOAM model competes with commercial software, like Ansys-Fluent. • Parametric analysis with the new model. Computational fluid dynamics (CFD) simulation is an effective tool to study the flow characteristics of a rotating packed bed (RPB) in comparison with the corresponding complicated, time-consuming, and expensive experiments. Detailed flow characterization of RPB enables the optimization of micromixing efficiency, thus its overall performance. Among various CFD models, the reliable proficiency of Euler-Euler model in describing the two-phase flow behavior of a packing media has been demonstrated. It is less computationally expensive and sensitive to the size and mesh resolution than other CFD models, such as volume of fluid (VoF) and Euler-Lagrangian models. In addition, the interfacial mass and momentum transfers between phases are considered without resolving the interface characteristics in this model. These features make the Euler-Euler model a suitable choice for large-scale and 3D simulations of an RPB. The primary purpose of this work is to develop a new Euler-Euler model in OpenFOAM to characterize two-phase flow behavior of RPBs. A new two-phase porous media model is coupled with the Euler-Euler model in OpenFOAM to properly predict drag forces between liquid–solid and gas–solid phases. The numerical model was verified and validated by two sets of global and local hydrodynamic experimental data collected from the literature. The new OpenFOAM model demonstrates a promising capability in adequately describing principal hydrodynamic parameters of RPBs, including the liquid holdup, velocity, and pressure drop. Parametric analyses with the aid of the developed numerical model delineated the effects of main operating parameters, such as rotating speed, liquid and gas volumetric flow rates, gas to liquid filling ratio, and packing/bed diameter ratio, on the hydrodynamics of an RPB. Performances of two and three-dimensional numerical models in hydrodynamic predictions of an RPB were also studied.