Like-drop collisions of biodiesel and emulsion diesel

Understanding the mechanism of spray combustion requires an understanding of the collision behavior of fuel drops. Previous studies have focused primarily on the collision of uniform droplets; however, a growing interest in biodiesel and emulsion diesel has necessitated the investigation of collisions among non-uniform droplets. In this study, we discuss the collision occurring between two identical drops with various quantities of biodiesel in diesel fuel (10% and 60%) as well as various quantities of water in diesel (10% and 30%). This study discusses collision behavior, bouncing, coalescence, reflex separation and stretch separation with respect to impact parameter (X) and Weber number (We). Our empirical results reveal that under low We number, bouncing is less likely to occur in drops of emulsion diesel than that in drops of biodiesel. Under conditions of similar viscosity, the collision of emulsion diesel droplets involves a larger coalescence region than that found in biodiesel. Furthermore, higher collision energy is required to achieve reflex separation for emulsion diesel droplets and with the same Weber number, a higher impact parameter is required to achieve stretch separation. (C) 2016 Elsevier Masson SAS. All rights reserved.