Forced ignition of laminar premixed spherical flames in evaporating fuel droplet mists

TL;DR

This paper develops a theoretical model to analyze the ignition process of spherical spray flames with fuel droplets, revealing how droplet addition influences flame strength and ignition energy under fuel-lean conditions.

Contribution

It introduces a novel model with two characteristic fronts to describe evaporation and ignition dynamics in droplet-laden flames, advancing understanding of spray ignition mechanisms.

Findings

Adding fuel droplets strengthens the flame.

Minimum ignition energy decreases with droplet addition.

Evaporation front evolution is characterized in the model.

Abstract

This study aims to build a theoretical model to describe the ignition process of spherical spray flame laden with fuel droplets under overall fuel-lean condition. Two characteristic fronts are introduced to reveal where the evaporation starts and ends in the ignition process. The results demonstrate that the flame has been strengthened with extra fuel droplet adding while the minimum ignition energy (MIE) is decreased. The evolution of the two evaporation fronts in the flame kernel and propagating branches has also be revealed coupled with the evaporation zone length.