Investigation on Droplet Evaporation Considering Radiation Heat Transfer by a Developed Lattice Boltzmann Model

Abstract

Suspended droplet evaporation in high temperature is common seen and widely used in various industries. Different from the previous lattice Boltzmann model of liquid-vapor phase change, a newly developed model which can consider radiation heat transfer is proposed and used to simulate the suspended droplet evaporation process. This model is verified by the theoretical solutions and compared with the D<sup>2</sup> law. It is found that the deviation between simulated results and the D<sup>2</sup> line is much more obvious under high vapor temperature and small droplet size. And, the radiation heat-transfer ratio during droplet evaporation can reach 45.6% in our simulation, which indicates the importance of radiation heat transfer in droplet evaporation and the necessity of coupling radiation heat transfer into the liquid-vapor phase-change model under high temperature. Also, effects of extinction coefficient β and scattering albedo w on evaporation process are discussed by detailed analysis of streamlines and temperature distribution. Our model and results will benefit the understanding of radiation heat transfer in droplet evaporation process.