A resolved CFD-DEM method based on the IBM for sedimentation of dense fluid-particle flows

Motivated by the interest in accurate simulation of dense fluid-particle flows, a resolved CFD-DEM method is developed by incorporating computational fluid dynamics and discrete element method (CFD-DEM) with the immersed boundary method (IBM). In this approach, the fluid phase is simulated by the CFD while the individual particles are analyzed by means of the DEM. The direct-forcing IBM, which satisfies the no-slip boundary condition and the divergence-free condition simultaneously, is introduced to handle the interactions between rigid boundaries and fluid with inherent ease of tracking drastically moving geometries by a set of Lagrangian points. The strongly coupled system is then achieved through the successive iterative procedure. A significant advantage of the proposed method is that the fluid phase is fully resolved around the particle phase and as a result, for dense particulate flows where the interaction effects on either phase is considerably strong, the essential influence of the wake flow on particles could be reflected truthfully. The gravity-induced sedimentations of particles are performed to demonstrate the accuracy of the presented resolved method, and the comparison with the results obtained by the conventional unresolved CFD-DEM method is also performed which reveals that the proposed method shows a superiority of the precise description of the fluid-particle interactions over the conventional method especially when the dense particulate flows are involved. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

A resolved CFD-DEM method is developed to accurately simulate dense fluid-particle flows by combining computational fluid dynamics and discrete element method with the immersed boundary method. This method allows for a fully resolved representation of the fluid phase around the particle phase, reflecting the true influence of the wake flow on particles in dense particulate flows.