Experimental investigation of evaporation characteristics of sessile fuel droplets on a hot surface

Abstract

Spilled fuel that comes in contact with hot surfaces can cause a fire, and to mitigate this type of fire, we researched the evaporation patterns and heat transfer mechanisms of fuel droplets on such surfaces. Glass heating substrates were used to experimentally investigate the evaporation behavior of acetic acid, ethanol, acetone, ethyl acetate, n-heptane, and cyclohexane. Infrared imaging technology and volume estimation method were used for the experimental analysis. The study revealed various thermal patterns on the surfaces of different droplets. Hydrothermal waves (HTWs), Bénard-Marangoni (B-M) cells, cyclic thermal patterns, and double-vortex thermal patterns were observed on different types of fuel droplet surfaces. The energy absorption and breakage of intermolecular hydrogen bonds are related to the formation of HTWs and B-M cells. As the height of the droplets decreased, the rate at which the six fuel droplets evaporated was observed to decrease initially and then increase. The results of this experiment indicate that the evaporation rate of droplets is largely determined by the saturation vapor pressure.