Prediction of the density and viscosity of biodiesel and the influence of biodiesel properties on a diesel engine fuel supply system

Biodiesel has been considering as promising fuel in the situation of ever-depleting fossil fuels and serious environment pollution. Beside clearly known advantages, high viscosity and density, and high surface tension are the acute disadvantages that need to be improved to use directly for an unmodified diesel engine. In this work, 24 samples of biodiesel-diesel fuel blends created by mixing respectively 5%, 10%, 20%, 40%, 50%, 60%, 75% and 100% of fractions of Coconut oil biodiesel (COB), Jatropha oil biodiesel (JOB), Waste oil biodiesel (WOB) in diesel fuel were used for experimental purposes. In the first stage, the effects of biodiesel fractions and temperature on kinematic viscosity and density were developed. In the second stage, the effects of kinematic viscosity and density on fuel supply system, fuel pump network, fuel filters, and spray characteristics (including penetration length (L-b ) and Sauter Mean Diameter (SMD)) were investigated. Obtained results of this study based on experimental correlation and mathematical equation showed over 95% of the confident level from a regression correlation equation regarding kinematic viscosity and density.