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 distribution of particle and fluid quantities in 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 EL simulation accuracy. The results show that, due to variations in feedback forces at individual particle locations, the forces computed in the EL method do not consistently correlate with those obtained from the PR simulations.