Numerical Prediction of Sauter Mean Diameter from Pressure Swirl Atomizer Using Eulerian Model

摘要

Atomizers are used in many engineering applications including spray combustion in furnaces, diesel engines, gasoline direct injection engines and gas turbine engines. Pressure swirl atomizers occupy a special position amongst other atomizers because they differ in quality of atomization, simplicity of construction, reliability of operation, low clogging and low expenditure of energy. Turbulence behaviour and the mean droplet size are indispensable considerations in the sprays and atomization process of pressure swirl atomizers. This paper presents entirely Eulerian modelling of two phase flow in a pressure swirl atomizer as a single multi-component phase with high density variations using Computational Fluid Dynamics (CFD) commercial code STAR-CD. The transport equations for the liquid surface density and liquid mass fraction are modelled for the flow and turbulent fields. Numerical results such as liquid mass fraction and liquid surface density are presented. The model also shows the results of atomization characteristics such as droplet velocity and predicts Sauter Mean Diameter (SMD) with reasonable order-of- magnitudes