Importance of considering interstitial fluid effects in the kinetic theory of granular flow for raceway formation prediction

A comprehensive comparison of Two-Fluid Model, Discrete Element Method and experiments for the simulation of single- and multiple-spout fluidized beds

“…Due to discrete nature of the CFD-DEM method, it can fully resolve the contacts in all regions, however in the TFM approach, closures are needed to sufficiently consider these interactions. In the commonly used TFM approach for modelling of the spout fluidized beds (Guo et al, 2021;Chen et al, 2019;Almohammed et al, 2014;Zhao et al, 2021;Wang et al, 2014;Wu et al, yyyy;Zhao et al, 2016;Zhao et al, 2022), interstitial fluid effect on the kinetic-collisional solids stresses and pseudo-thermal energy flux has been ignored while studies of Wartha et al (Wartha et al, 2022), Agrawal et al (Agrawal et al, 2001) and Schneiderbauer et al reveal its importance. Furthermore, conventional frictional solids stresses models based on Coulomb's law (Schaeffer, 1987;Syamlal et al, 1993;Johnson and Jackson, 1987;Johnson et al, 1990;Srivastava and Sundaresan, 2003;Benyahia, 2008) manifest order-zero dependence on the rate of deformation in the quasi-static granular regime and are suitable just for dense regimes (Van Wachem et al, 2001).…”