Development of a filtered drag model considering effect of the solid shear rate

Abstract

This study investigates a 2D gas–solid fast fluidized bed of typical Geldart A particles using highly resolved simulations with two-fluid model. The results show that the solid shear rate has a considerable impact on the orientation of the meso-scale structures and hence on the filtered drag force. On the basis of the correlation for the filtered drag force established in the literature using the traditional markers (such as filtered solid volume fraction, filtered slip velocity and filter scale), a correction correlated with the solid shear rate in the direction of gravity is proposed for better prediction of the filtered drag force. The corrected model is shown to produce improved results in posterior tests of flows in different fluidization regimes including bubbling, turbulent and fast fluidization.