Assessment of a coupled VOF-Front-Tracking/DEM method for simulating fluid–particles flows

Abstract

In this paper we introduce a one-fluid numerical method for the simulation of dense particle–fluid flows. The method uses a front tracking algorithm coupled to a viscous penalty method to enforce the rigidity constraint. A modified version of the collision model of Mohaghegh and Udaykumar (2019) is used to model both collisions and lubrication forces. This approach allows us to greatly reduce the amount of ad hoc numerical parameters required to perform the simulations. For validation purpose, we successfully reproduce several experimental and numerical benchmarks including the settling case of a sphere in an enclosed box performed by ten Cate et al. (2002), the bouncing motion against a planar surface performed by Gondret et al. (2002), the study of the fluid–solid fluidized bed performed by Aguilar-Corona (2008), and the particle-resolved simulations of the same case performed by Ozel et al. (2017). The method is shown to realistically reproduce the motion of a settling and a bouncing sphere in a quiescent fluid. The statistical study of the fluidized bed showed excellent agreement with the experimental data and the fluidization law: the solid volume fraction, the solid velocity variance and the anisotropy coefficient are accurately reproduced by our simulations.