Inertial Number-Based Drag Model and Its Application in Simulating the Fluidization of Geldart B and D Particles

The Gidaspow drag model that combines the Ergun and Wen-Yu empirical correlations is widely used in gas-solid two-phase flows in the literature. It is believed that fluid-particle drag should be a continuous function of both the solid volume fraction and the Reynolds number. In the Gidaspow model, however, the transition of the two correlations is discontinuous at the solid volume fraction of 0.2. A few later models smoothed this transition, though with arbitrarily chosen functions and parameters. A new drag model with a transition based on the inertial number is proposed in this paper. Predictions of this new drag model were compared to those from other drag models in the settings of fluidization of Geldart B and D particles and a riser. Simulation results show that the inertial number-based drag model is a viable and accurate alternative to the original Gidaspow model and the later models.