Spray Patterns and Injection Characteristics of Gas-Centered Swirl Coaxial Injectors

Abstract

Spray characteristics of gas-centered swirl coaxial injectors, which are commonly used in staged combustion cycle engines, are investigated numerically and experimentally. The spray angle and the spreading angle are the quantitative parameters selected for experimental and numerical studies, respectively. Various gas/liquid Reynolds numbers are adopted for the operating conditions. For a fixed gas Reynolds number, the spreading angle increases with the liquid Reynolds number. Through the comparative study of the spray angle from water/air experiments, the spreading angle is analyzed for different momentum flux ratios (MFRs). The comparison of the spray and spreading angles for different MFRs shows good agreement. Modeling and study of gas–gas flow is a useful approach to understanding spray characteristics of gas–liquid flow.