Numerical study for the spray characteristics of diesel engine powered by biodiesel fuels under different injection pressures

Abstract

Great attention is directed towards the study of the spray phenomena theoretically and experimentally due to its dramatic effect on the combustion process that occurred in an internal combustion engine, in particular, the diesel engine. The spray macroscopic characteristic of diesel engines fueled with two different biodiesel fuels in addition to nominal diesel under various injection pressures has been investigated numerically in this work. The selected biofuels are Rapeseed methyl ester (RME), Waste cooking oil methyl ester (WCOME). The Russian simulation software Diesel-RK is used in this work. Four different injection pressures are used which are 200, 500, 800 and 1000 bar respectively. It is found that RME has higher spray penetration with a narrow spray angle due to high viscosity and large momentum compared to diesel fuel. The results reported that biodiesels have greater Sauter mean diameter (SMD) compared to pure diesel because of their higher viscosity and surface tension. Promising reduction in SMD comes with WCOME as the injection pressure increases. Cylinder pressure along with heat release is reduced in the case of biodiesel due to the reduction in heating values. The lowest ability to produce smoke is recorded for WCOME where 93% reduction is achieved followed by a 57% reduction for RME as compared to diesel. The obtained results are compared with the results of other researcher and the convergence between them is observed.