Effect of air swirler profile on spray characteristics

Pressure swirl atomizers are widely used in gas turbines and liquid propellant rockets to obtain improved atomization. In these atomizers, the liquid to be atomized enters through tangential inlets producing a swirling motion inside a swirl chamber and creates a central gas core surrounded by a liquid sheet that spreads radially outward from the orifice exit. In a typical gas turbine combustorcoaxially fitted swirler-atomizer assembly is used for better performance. In this paper, an experimental study has been conducted to investigate the effect of the swirler profile on a co-axial hollow cone spray. A coaxially fitted air swirler and atomizer assembly is used for the analysis. High speed imaging is used to capture the sharp images of spray and for the calculation of spray cone angle. Phase Doppler Interferometer (PDI) is used to analyze SMD variations. Significant change in spray characteristics is observed with different air flow rates and swirler shapes.