Similarity Analysis of Droplet Evaporation Trajectory in High-Temperature Gas Flow

In this study, a similarity analysis of droplet evaporation trajectory in high-temperature air crossflow based on numerical calculations was conducted. The procedure used for modeling the evaporation of a water droplet involved the use of a low boiling point liquid droplet. The trajectories of water and acetone droplets over an extensive temperature range of 695–1194 K were investigated, and the relationships for the corresponding parameters of the two different droplets, as well as the scale effect, were discussed. The results identify the existence of a comparative trajectory for different kinds of droplets, as well as the main dimensionless numbers governing the trajectory, by determining the Reynolds, Stokes, and Nusselt numbers. For each given gas flow Reynolds number, the droplet evaporation trajectory has a unique correspondence with the airflow temperature. Given this, a method of calculation to determine the modeling parameters of the droplet and crossflow was proposed. The applicability of the similarity modeling method of a single droplet to the spray droplets was examined, from which the spray structure in high-temperature crossflow was obtained.