Modeling particle-fluid interaction in a coupled CFD-DEM framework

TL;DR

This paper introduces a novel CFD-DEM coupling method that explicitly models body forces on fluid and particle interactions, validated through benchmark tests and settling velocity analysis.

Contribution

The work presents an innovative approach to particle-fluid interaction modeling by explicitly including body forces in a CFD-DEM framework, improving accuracy.

Findings

Accurately reproduces Stokesian dynamics

Validates against analytical solutions

Effectively predicts particle settling velocities

Abstract

In this work, we present an alternative methodology to solve the particle-fluid interaction in the resolved CFDEM coupling framework. This numerical approach consists of coupling a Discrete Element Method (DEM) with a Computational Fluid Dynamics (CFD) scheme, solving the motion of immersed particles in a fluid phase. As a novelty, our approach explicitly accounts for the body force acting on the fluid phase when computing the local momentum balance equations. Accordingly, we implement a fluid-particle interaction computing the buoyant and drag forces as a function of local shear strain and pressure gradient. As a benchmark, we study the Stokesian limit of a single particle. The validation is performed comparing our outcomes with the ones provided by a previous resolved methodology and the analytical prediction. In general, we find that the new implementation reproduces with very good accuracy the Stokesian dynamics. Complementarily, we study the settling terminal velocity of a sphere under confined conditions.