ID 226

Enhanced burning rate of jet fuel surrogate seeded with nanoparticles

 

Abstract:

In the present work, combustion dynamics of jet-fuel surrogate droplets laden with nanoparticles is investigated. N-dodecane; widely accepted surrogate of jet-fuels such as Jet-A etc is chosen as base fuel and alumina (Al2O3) nanoparticles are utilised as nanoaddititves. Dilute particle loading rates varying between 0.1%-1% by weight are considered. Droplet flame and shape oscillations are captured using simultaneous high-speed imaging. Internal ebullition in burning droplets is acquired through volumetric illumination of the droplets. Comparative investigation between pure dodecane and dodecane seeded with alumina nanoparticles reveals enhanced vaporisation and secondary atomisation of nanofuels. Formation of micron size aggregates of nanoparticles during combustion act as incipient of heterogeneous boiling. In nanofuels, rupture of formed bubbles resulting daughter droplets ensures rapid transfer of fuel parcels from droplet surface to flame envelope. This mechanism bypasses the diffusive limitations resulting in enhanced burning rate of nanofuels. Local as well as global flame perturbations are observed in response to these secondary ejection events although a time lag exists between these two occurrences. Final combustion residue is analysed using scanning electron microscopy (SEM). Strong variation of surface morphology is manifested with increase in nanoparticle particle loading rate.