Impact and boiling characteristics of a droplet on heated surfaces: A 3D lattice Boltzmann study

Abstract

• Four typical regimes are numerically reproduced for the first time. • The vapor bubble nucleation, growth, coalescence, and burst are captured. • The dependence of heat transfer on the bubble dynamics is presented. • Three different rebound types are observed and analyzed. Droplet impingement and boiling on heated surfaces play an important role in many industrial applications. Due to its complexity in nature, it is challenging to simulate the process of droplet impact on heated surfaces involving phase change. In the present work, a three-dimensional numerical simulation based on lattice Boltzmann method (LBM) is applied to analyze the dynamic and thermodynamic behaviors of droplet impact on heated surfaces. The process of vapor bubble nucleation, growth, coalescence, and even burst at the interface of the droplet can be successfully captured, and four typical regimes are numerically reproduced, which include film evaporation, nucleate boiling, transition boiling, and film boiling. Due to the idealized smooth surface applied here, a constant contact angle (CCA) model is observed during the process of droplet evaporation, and the time evolution of normalized droplet volume and spreading factor in the evaporation stage are consistent with the sessile droplet evaporation. When the bubble nucleation occurs in the droplet, the droplet interface is seriously distorted, and the heat transfer performance exhibits a strong dependence on vapor bubble dynamics. In addition, according to the numerical results, three different rebound types, including burst rebound, partial rebound, and complete rebound, are observed and analyzed in detail.