Generation Characteristics and Regulation Mechanisms of Monodisperse Droplets of JP-10-Based Nanofluids via Drop-on-Demand Technology

JP-10 is a pivotal high-density hydrocarbon fuel for advanced aerospace propulsion systems. Doping aluminum nanoparticles to prepare nanofluid fuels is a promising route to enhance its energy density and combustion performance, yet the droplet formation mechanism of such multiphase fuels remains poorly understood, hindering single-droplet combustion research and atomization system optimization. This work constructed a piezoelectric drop-on-demand (DOD) monodisperse droplet generation platform integrated with phase Doppler anemometry (PDA) and high-speed imaging. Using Al/JP-10/OA nanofluids with aluminum mass fractions of 0.1 wt. %, 0.5 wt. % and 1.0 wt. %, we systematically explored the effects of liquid flow rate, driving frequency and particle concentration on droplet size, size uniformity and ejection velocity. In this work, Al/JP-10/OA nanofluids with aluminum mass fractions of 0.1 wt. %, 0.5 wt. % and 1.0 wt. % were tested under liquid flow rates of 1.1–1.5 mL/min and driving frequencies of 10–50 kHz, with measured droplet diameter ranging from 241.04 μm to 292.26 μm and ejection velocity ranging from 1.65 m/s to 2.45 m/s. The results demonstrate that average droplet diameter increases linearly with flow rate and decreases monotonically with driving frequency. Compared with the 0.1 wt. % nanofluid, the 1.0 wt. % nanofluid shows a 4.4% larger droplet diameter and 12.1% lower ejection velocity, while the 0.1 wt. % sample retains excellent monodispersity with a size Span below 0.098. The multi-scale regulation mechanisms involving viscous variation, shear-thinning rheology and particle agglomeration are further clarified. This study provides fundamental data and theoretical support for atomization design of nanofluid aviation fuels.