A scale-independent modeling method for filtered drag in fluidized gas-particle flows

Abstract

A scale-independent modeling method for filtered drag force is proposed for coarse-grid simulation of fluidized gas-solid flows based on the fine-grid data generated using kinetic theory-based two-fluid method in periodic sedimentation systems. In the modeling process, the filtered solid volume fraction at a larger scale whose side length is three times of the filter size is introduced as a new marker. New developed closures show an excellent performance in a priori test, and exhibit a fairly good agreement with the fine-grid data and the experimental data in a posteriori test for three typical fluidized regimes including bubbling, turbulent and fast fluidized beds. Furthermore, the available correction methods to consider the effect of the material properties via adding a multiplicative factor are tested. The results show that these correction methods are not suitable for the considered cases.