This study presents new numerical drag models with which to analyze the sensitivity of mesoscale structural parameters in bubbling,turbulent,and circulating fluidized beds.The drag models are derived using the method of transfer-coefficient-based structural parameters (TC-SP).Analyzing the sensitivity of the structural parameters reveals that the coefficients associated with drag are more sensitive to parameters in the dense phase than to those in the dilute phase,especially the superficial slip velocity.On the basis of these results,the TC-SP drag model is simplified further.Interestingly,despite having half the number of parameters of conventional structure-based drag models,the simplified TC-SP drag model achieves simulation results that are equally or more accurate.With simple calculations and improved accuracy using coarse grids,the model reported in this study is capable of predicting the hydrodynamics of the three types of fluidized beds.