Effects of design variables on the liquid breakup and the atomization characteristics of rotary atomizers for small gas turbine combustors

Slinger nozzles are a class of rotary atomizers applied in gas turbine combustors, which atomize liquid fuels using the rotational kinetic energy of the turbine shaft. In this study, the influence of design and operating variables on the spray characteristics of the slinger nozzle was investigated to predict the atomization performance inside the gas turbine combustor. The nozzle radius (R_o = 49 mm, 40 mm), the number of nozzle orifices (N = 4, 6, 8, 10, 12), and the diameter of the nozzle orifice (d = 3 mm, 4 mm) were changed as design variables. A high-speed camera was applied to visualize the spray behavior of the nozzle, and the droplet size was measured using a two-dimensional phase Doppler particle analyzer. The experimental results showed that the spray characteristics of the slinger nozzle are highly related with the nozzle design variables. Correlation maps applicable to predict the influence of design variables on slinger nozzle spray characteristics were presented. The effects of design variables on the Sauter mean diameter (SMD) were quantified using multiple regression analysis, and a simplified equation to predict the slinger nozzle atomization performance was presented.