On the Modelling 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, which relies on a comprehensive set of free spray measurements. Distinct wall and crossflow temperatures are analysed systematically to evaluate the in fluence of droplets evaporation on the nal outcome of spray impingement, and, particularly, on the distribution of the thin liquid lm over the surface. The present computational model already proved to deliver accurate predictions of the spray/wall interactions under different conditions. In this work, the conditions are extrapolated to a heated environment, which reproduce more adequately what is found in in-cylinder situations. The computational model is adapted to meet the new requirements and perform within the range of conditions for which it is now formulated. The analysis shows that higher temperatures lead to smaller impinging droplets, an increase in the number of depositing droplets but a decrease in the fraction of mass of particles contributing to the liquid film; and a more uniform distribution of the liquid layer over the surface.