Modeling of Evaporating Sprays Impinging onto Solid Surfaces

Abstract

The present paper presents a numerical study on evaporating droplets impinging onto a solid surface through a crossflow. The characteristics of the initial spray are established by employing an empirical procedure that relies on a comprehensive set of free spray measurements. Distinct wall and crossflow temperatures are analyzed systematically to evaluate the influence of droplet evaporation on the final outcome of the simulation and, particularly, on the distribution of the thin liquid film that forms over the surface due to the deposition of incident droplets. The present computational model already has been proven to deliver accurate prediction results of the spray-wall interactions under different conditions. In this work, the conditions are extrapolated to a heated environment, which more adequately reproduces what is found in in-cylinder situations. The computational model is adapted to meet the new requirements and to perform within the range of conditions for which it is now being formulated. The analysis shows that higher temperatures lead to a decrease in the size of impinging droplets, an increase in the number of depositing droplets, a decrease in the fraction of mass of droplets contributing to the liquid film, and a more uniform distribution of the liquid layer over the surface.