Experimental study on spray characteristics of aviation kerosene RP-3 in a radial rotary atomizer

In this work, the spray behaviors of a rotary atomizer with round-shaped injection orifices are experimentally investigated to study the breakup mechanism and spray characteristics using RP-3 as the liquid fuel. The breakup process of the liquid is visualized by the backlight shadow imaging method, which also provides the measurements of liquid breakup length and penetration height. The injection mode of the liquid film is observed using the front-light illumination method. The droplet size and distribution are measured using the laser particle size analyzer at various radial locations. Three typical breakup modes are identified: the ligament breakup mode, bag breakup mode, and shear breakup mode. Aerodynamic Weber number (We_d) and momentum flux ratio (q) are used to elaborate the liquid breakup regimes. Results of droplet sizing indicate that the Sauter mean diameter decreases with a higher rotational speed and slightly varies with the volume flow rate. A correlation between liquid breakup modes and non-dimensional droplet size is established based on We_d and q. This study presents some significance for understanding the impacts of the rotational speed and volume flow rates on the spray performance of actual aviation fuels in rotary atomizers. (Figure presented.).