Bridging scales in droplet evaporation on hot particles: A Volume‐of‐Fluid‐informed correction for coarse‐grid models

Abstract

The spreading and evaporation of liquid droplets on hot particle surfaces are critical to liquid‐sprayed fluidized bed design. While coarse‐grid approaches (CFD‐DEM, Euler–Euler) are commonly used in reactor‐scale simulations, they lack resolution of microscale interfacial phenomena at the single particle level. This work performs high‐fidelity Volume‐of‐Fluid (VOF) simulations coupled with an interface evaporation model to investigate droplet impact and evaporation on heated spherical particles over wall temperature of 250°C–400°C and Weber number of 8–84. Results show that total evaporation time is insensitive to particle temperature, while droplet morphology and evaporated mass strongly depend on wall temperature and Weber number. Moreover, an effective evaporation area coefficient derived from VOF simulations is introduced as a correction factor for macroscopic models, enabling coarse‐grid simulations to retain essential microscale physics without explicitly resolving interfaces. It is expected to improve predictive accuracy for simulation of liquid‐sprayed fluidized bed with coarse‐grid approaches.