CFD-DEM modeling and simulation of ellipsoidal particles in a gas–solid spouted bed

Gas-solid spouted beds are widely used in fields such as biomass combustion due to their excellent heat transfer performance and gas–solid mixing efficiency. The size, shape, and density of biomass particles play a crucial role in the two-phase flow and combustion kinetics processes. However, existing research has primarily focused on spherical biomass particles, and the fluidization mechanisms of non-spherical particle systems has not yet been fully understood. Therefore, studying the fluidization characteristics of non-spherical particle systems is of great significance for advancing fluidization theory and optimizing the design of spouted bed reactors. This study employs the computational fluid dynamics (CFD) and discrete element method (DEM) framework to investigate the fluidization characteristics of ellipsoidal particles and validates the reliability of the numerical model through high-speed photography experiments. The results indicate that as the inlet gas velocity increases, the average bed height and void fraction of ellipsoidal particles in the spouted bed gradually increase, and the particle mixing quality is enhanced. As the initial accumulation height increases, the average bed height and volume fraction of ellipsoidal particles gradually increase, while the overall particle mixing quality decreases. Particles with orientation angles between 30° and 45°constitute a smaller proportion, whereas those with orientation angles between 75° and 90° constitute a larger proportion.