Effects of multiple droplet interaction on droplet vaporization in subcritical and supercritical pressure environments

Abstract

Dilute- and dense-cluster droplet vaporization is studied numerically over a 1–60-bar pressure range. The present model applies the “sphere of influence” concept to account for multiple droplet interaction. High-pressure effects are dealt with by solving both gas- and liquid-phase transient flows, as well as by including the effects of ambient gas solubility, property variation, thermodynamic nonideality, and transient diffusion. N-pentane dilute spray results reveal that variations in predicted droplet lifetime are qualitatively in agreement with previous single droplet vaporization studies. With dense spray n-pentane, droplet lifetime is significantly prolonged at low initial ambient pressures, monotonically decreasing as initial ambient pressures rise. It is predicted that saturation occurs only for a dense enough cluster of droplets. Dilute sprays at initially high ambient temperatures and pressures can reach the critical mixing state, unlike dense sprays in which the ambient temperature and pressure are substantially reduced due to cooling by droplet vaporization.