Evaporation and Ignition of a Fuel Droplet on a Hot Surface : Part 3, Effects of Initial Droplet Diameter

Abstract

The evaporation and ignition process of a single droplet of n-cetane on a hot surface has been investigated in detail in the range of the hot surface temperatures 300550°C, and of the initial droplet diameters approximately 0.73.3 mm. The modes of evaporation of droplet are observed through high speed cine-photography. It is found that the upper limit of a hot surface temperature, at which the mode of evaporation of droplet contacting with hot surface disappears, shifts to a lower temperature with decreasing the initial droplet diameter. The ignition delay time also increases abruptly at this surface temperature. Furthermore, the effects of the initial droplet diameter on the evaporation life time and the ignition delay time have been delineated from the observed results, and the critical diameter of the droplet below which the ignition does not occur has been determined experimentally.