LAUSR

Abstract High-energy-density fuels are promising fuels for advanced aero engines, especially rotary engines, in which atomization characteristics play a crucial role in fuel practical application. This work experimentally investigated the basic spray characteristics mainly including spray angle, droplet concentration, velocity, and size distribution of two liquid fuels JP-10, HEF-1 and one slurry fuel HEF-2 by PDPA technique using a fuel slinger under 10000–25000 rpm. Effects of fuel physical properties (fuel type, density, viscosity, surface tension, etc) and control parameters (rotational speed and fuel flowrate) on atomization characteristics were discussed. The results showed that the droplet number was parabolic distribution for each fuel and significantly increased with the elevated rotational speeds. Slurry fuel had the largest droplet number near the spray center due to the fragmentation effect of nano-Al particles. For liquid fuels, viscosity determined the droplet breakup below 10000 rpm. Spray angle and droplet velocity negatively related to fuel viscosity. Besides, elevated rotational speeds promoted average droplet velocities, while lowered spray angles. Overall, Sauter mean diameter (SMD) of each fuel greatly depended on fuel viscosity was arch bridge-type distribution. Slurry fuel possessed a smoother distribution with much larger SMD (55–65 μm) than liquid fuels (20–45 μm). Furthermore, the average SMD (ASMD) of JP-10 and HEF-1 gradually decreased from 58 μm to 40 μm, and 44 μm–35 μm, respectively as rotational speeds increased. Additionally, they increased by less than 20% when flowrates increased from 0.15 Lpm to 1.20 Lpm. Nevertheless, slurry fuel HEF-2 had an ASMD around 65 μm which remained almost unchanged with varying rotational speeds and flowrates.