Effect of water-in-heavy fuel oil emulsion on the non-reacting spray characteristics under different ambient conditions and injection pressures: A CFD study

Abstract

Emulsified fuel is one of the main strategies to substitute the conventional fossil fuel for the purpose of emission control and enhancement of fuel effciency. Accordingly, non-reacting spray characteristics of water-in-Heavy Fuel Oil (HFO) emulsion are numerically investigated in the present study via CFD analysis. Three different volumetric percentages of water in HFO are investigated and compared with pure HFO. Effects of four different injection pressures on injected fuel spray characteristics are studied. Moreover, inuences of three different ambient back pressures and two ambient temperatures are considered. For these purposes, the characteristics of spray penetration, cone angle, volume, and SMD are evaluated through the analyses of non-dimensional numbers. For modeling the interaction of the fuel discrete phase and the gaseous continuous phase, Eulerian-Lagrangian multiphase formulation in OpenFOAM CFD toolbox is implemented. Fuel droplet tracking in Lagrangian scheme is applied by Lagrangian Particle Tracking method. Also, KH-RT as a hybrid breakup model for liquid fuel core breakup and standard model of κ-ϵ " in RANS for turbulence modeling are utilized. Numerical results are validated against existing experimental data with suitable accordance. Longer spray penetration length, larger cone angle, and greater spray volume are achieved for the emulsified fuels.