Ignition characteristics of kerosene droplets with the addition of aluminum nanoparticles at elevated temperature and pressure

The effects of various ambient pressure and temperature conditions on the ignition characteristics of kerosene-based nanofluid droplets were investigated experimentally. Individual kerosene droplet containing 0.1 or 1% by mass was mounted on the tip of silicon carbide (SiC) fiber and exposed to ambient temperatures in the range of 400-700 °C and ambient pressures in the range of 0.1-2.5 MPa under normal gravity. An increase in ambient pressure was observed to reduce the ignition location distance below a droplet. The ignition delay times of pure kerosene droplets were also examined for comparison. The results showed that the ignition delay time of Al NPs-laden kerosene droplets decreased exponentially with increasing temperature, as did that of pure kerosene droplets. An ambient pressure increase from 0.1 to 2.5 MPa led to a decrease in the lowest ambient temperature for ignition from 800 to 400 °C. At pressures greater than 1 MPa, the ignition delay times of droplets with 1% Al were shorter than those of pure kerosene and kerosene with 0.1% Al. Furthermore, as the ambient pressure increased from 0.1 to 2.5 MPa, the ignition delay was found to decrease and then increase exceeding the limiting pressure.