Surface tension, light absorbance, and effective viscosity of single droplets of water-emulsified n-decane, n-dodecane, and n-hexadecane

Abstract

Water-emulsified liquid fuels have been used occasionally in combustion systems to control flame temperature and NOx emission. Atomization characteristics are important for efficient combustion of emulsified fuels, and they are affected by the mechanical properties of the emulsion. The dynamic behavior of an emulsion droplet is affected by the micro-droplets dispersed within the emulsion, and the actual properties of the emulsion are of interest. Recently, a new dynamic method using a pulse laser was developed based on the Taylor's analogy breakup model. In this study, surface tension, light absorbance, and viscosity were evaluated for two emulsified fuels (n-decane and n-hexadecane), and their results compared with those of n-dodecane from the previous study. Three independent ordinary methods and the dynamic method were employed to measure the emulsion properties. Actual light energy absorbance, more reliable surface tension, and effective viscosity of emulsion could be predicted through the dynamic method. Finally, a simple empirical equation was suggested for the prediction of the effective viscosity of emulsion. The applicability of the proposed dynamic method was verified conclusively, and the most effective properties of single emulsion droplets were determined.