Spray characteristics of axially-vaned slinger atomizer in air crossflow

Slinger atomizers are frequently employed to facilitate fuel spray atomization in aeroengine combustors. Unlike traditional radial slinger atomizers that induce the limited interaction between the rotating fuel and the surrounding air, this study proposes an innovative approach by incorporating axial vanes into the slinger rotor to potentially enhance fuel atomization performance. A comprehensive analysis of the spray characteristics of an axially-vaned slinger atomizer in air crossflow is numerically conducted, focusing on the effects of axial vane, rotor-stator axial clearance, and fuel inlet conditions. Results demonstrate that axially-vaned slingers outperform radial slingers by enhancing air swirl strength to disrupt the fuel jet, reducing the average droplet size by 25 % at 30000 rpm. Furthermore, positioning fuel nozzles farther from the rotor wall can mitigate the potential risk of surface thermal erosion. Fuel leakage through the rotor-stator clearance decreases from around 80 % at 10000 rpm to below 5 % at 30000 rpm and becomes negligible at 40000 rpm, thereby enhancing fuel-air mixing efficiency. Introducing supercritical fuel at the inlet facilitates its transition into a gaseous state within the slinger inner chamber, thereby markedly amplifying mixing efficiency. Nonetheless, this improvement is accompanied by a reduction in fuel flow rates. A significant aspect to consider is the heightened risk of substantial wall erosion due to pronounced leakage through the rotor-stator axial clearance. This study presents novel perspectives on improving the efficiency and ensuring the operational safety of rotary atomizers, thereby offering valuable guidance for the design of power and propulsion systems.