Abstract

Liquid atomization is widely used in industrial applications such as aerospace, combustion, pharmaceutical, spray coatings, and surface engineering. The main concern of atomization is to have a controllable and uniform spray. In suspension plasma spraying technique, where the attempt is to reach nano-scaled uniform coatings, there is a vital demand to produce a uniform and non-pulsating spray. Effervescent atomizers, in which a gas is bubbled into the bulk liquid through an aerator, have shown to be a technological alternative to the conventional atomizers when atomization of liquids with large variety of viscosity and density is required. Thus, understanding the behavior of gas and liquid flow through the nozzle is crucial to predict the condition of outcoming spray. The objective of this study is to numerically investigate the two-phase flow inside the effervescent atomizers. Using the incompressible Eulerian/Eulerian approach, the three-dimensional structure of two-phase flow inside an aerated-liquid injector is modeled. The behavior of liquid film in the discharge passage is investigated using different Gas to Liquid mass flow Ratios (GLR). These numerical results are compared with the experimental data available in literature. The effect of nano-sized solid particles concentration on the liquid film thickness at the exit of the atomizer is studied through the change in liquid bulk density and viscosity