Dense Sprays with a Focus on Atomization and Turbulent Combustion

Abstract

This paper presents a brief overview of recent research conducted by our group to advance current understanding of primary and secondary atomization as well as the turbulent combustion of sprays. The focus is on air-blast atomization. The burner employed exploits the benefit of recessing a liquid-injecting needle into the primary air-blast annulus to transition the spray exiting the burner from dilute to dense. A pilot is used to stabilize the flame to the burner which is sitting in a co-flowing stream of secondary air. Direct links are found between the wave instabilities and the size of the fragments shed from the liquid core. In the secondary atomization zone, the statistics of three types of fragments, namely droplets, ligaments and irregular fluid shapes are provided. This approach may provide a platform for the modelling of denser spray flames without the need to account for primary atomization. For reacting cases, mean temperature measurements are presented. This burner (referred to as the needle spray burner) is employed to stabilize dilute and dense spray flames.