An Evaluation of Two-way Coupled Euler-Lagrange Methodology through Direct Comparison with Particle-Resolved Simulations

The Two-way Coupled Euler-Lagrange (EL) methodology is an efficient computational tool for investigating multiphase flows, enabling simulations with tens of millions of particles without Reynolds number limitations. This method resolves the fluid motion on scales larger than a filter length scale, which typically exceeds the particle size and the inter-particle spacing. However, EL simulations require closure models to account for unresolved scales. This work compares particle-resolved (PR) and EL simulations to assess the accuracy of EL solutions. We examine how well EL simulations capture the statistical evolution of multiphase flows by comparing them with PR solutions. The focus is on modeling the force on particles and understanding the influence of the filter scale on simulation accuracy. A significant finding is that while EL simulations can predict fluid velocity and particle forces, they capture particle-to-particle force variation less accurately. The study also explores correlations between EL and PR force variations to improve closure models.