Comparative Study of Equilibrium and Nonequilibrium Evaporation Models for Vaporizing Droplet Arrays at High-Pressure

Abstract

Combustion performances and emissions are mainly influenced by atomization, evaporation of fuel droplets and mixing of fuel and air. In particular, vaporization is often the rate-controlling process and is directly related to the specific fuel consumption of the engine and to pollutant formation. The present work focuses on two competing factors, which strongly influence the vaporization process, specifically: drop-drop interactions and high-pressure effects. Numerical predictions from equilibrium and nonequilibrium vaporization models are compared with the experimentally determined evaporation rate of droplet arrays at high-pressure conditions. The objective is to improve the predictive capabilities of spray models by introducing drop interaction effects in the modeling and by verifying which formulation of heat and mass transfer is able to model adequately their mutual interdependence at high-pressure.