An investigation on the similarity theory framework for CFD-DEM simulation in a stirred liquid bath containing particles

The coupled computational fluid dynamics-discrete element method (CFD-DEM) simulation is regarded as an effective tool for investigating fluid-solid coupling problems. However, large-scale CFD-DEM simulations face significant challenges due to computational efficiency limitations. In this paper, a similarity theory framework for CFD-DEM simulations is proposed to ensure the similarity of fluid flow, particle motion and particle collision in solid-liquid two-phase flow system. Based on the structure of the physical simulation model of a hot-dip galvanizing pot, both basic and scaled-down numerical models are developed. The validity of the theoretical framework is verified through fluid dynamics, particle dynamics, and inter-particle contact mechanics. The results indicate that both the basic and scaled down models exhibit similar behaviors in fluid-particle flow, particle accumulation morphology and particle suspension characteristics. Additionally, the CFD-DEM simulation similarity theory framework significantly reduces the number of simulated particles by 63.4 %, while accurately replicating the original system.