Evaluation of Drag Models for Simulating Gas-Solid Fluidization of Geldart A and B Particles

In the gas-solid fluidized bed reactors, two-fluid model based on the kinetic theory of granular flow exhibits a significant dependence on drag models, especially for Geldart A and B particles. Many drag models are available in the literature, which have been reported to work for different systems. In this work, the three-dimensional simulations by two-fluid model for gas-solid fluidized beds, including bubbling fluidized bed (BFB) and circulating fluidized bed (CFB), were established. The evaluation of different drag models for Geldart A and B particles was carried out. By using the different single particle drag coefficient C_d, the calculation for five drag models (Gidaspow, Symlal, HKL, BVK and De felice) were performed. Comparison with the available experiment data, the most accurate drag model for predicting mesoscale structures (i.e., bubbles and clusters) has been acquired. The results of this work provide a guideline for choosing appropriate drag models for simulating Geldart A and B particles in the gas-solid system and develop the more accurate drag models by changing the single particle drag coefficient C_d. In the further study, we will explore the modification of drag model due to the effect of mesoscale structures and the drag model in the liquid-solid sytem.