Interface-capturing numerical studies of multicomponent spray and droplet vaporization

Abstract

Motivated by the goal of improving the theoretical understanding of spray combustion, this work studies the vaporization of multicomponent sprays and droplets. It presents an exploratory study of spray vaporization but focuses on the physics of droplet vaporization. For real fuels, which consist of multiple chemical species, or components, the combustion properties of the fuel change over time depending on which components are most prevalent in the vapor. This variation in vapor composition is driven primarily by differences in the vaporization rates of the components. Although much is known about the vaporization of fuel droplets, many studies have relied on simplifying assumptions. Recent work has begun to demonstrate that some neglected phenomena, such as droplet deformation and internal liquid flow, have appreciable effects on fuel-droplet vaporization.

This work investigates how droplet deformation and internal flow affect the vaporization of a Jet-A surrogate. It uses an in-house finite-volume code to perform interface-capturing direct numerical simulations of liquid–gas flows. The code simulates the dynamics of multicomponent fuel vaporization from first principles by directly solving the governing conservation laws for mass, momentum, and energy transport. The results quantify how these phenomena affect vaporization in terms of appropriate nondimensional groups, such as the Weber number and circulation strength, and discuss the resulting trends.