Atomization characteristics of impinging jets of gelled propellant containing aluminum particles

Spray processes find extensive applications across various industrial fields. In recent years, heightened requirements for engine performance have driven increased research interest in gelled fuels containing metal particles. This gelled fuel exhibits shear-thinning non-Newtonian fluid behavior, yet its atomization characteristics remain poorly understood. This simulation examines the influence of different jet velocities and varying metal additive concentrations on the atomization characteristics of gelled Jet A-1 fuel, with comparative analysis against ungelled Jet A-1 fuel. The results demonstrate that increasing jet velocity significantly reduces droplet size, with ungelled Jet A-1 showing more stable size reduction than gelled Jet A-1. Gelled Jet A-1 displays greater instability in atomization morphology and more readily transitions to a fully developed pattern. Post-atomization droplets introduce vortices into the downstream flow field, thereby enhancing turbulence intensity in downstream regions, which is the energy transfer mechanism from liquid to gas phase. Additionally, the study reveals that the influence of metal additive concentration on atomization outcomes is non-monotonic. This complexity arises because metal additives concurrently alter both the viscosity and density of the gelled propellant, resulting in dual effects on final atomization performance.