Analytical study for palm-jatropha biodiesel spray characteristics

This papaer presents analytical evaluation of biodiesel blends with diesel fuel using indirect injection spray injector. The biodiesel under study is a 60:40% blend of used frying oil (from palm) and jatropha oil. The reason for selecting this composition is the best trade off for obtaining oxidation stability and saturation properties. Use frying oil is selected for economical reason. The pysicochemical properties, i.e. density, surface tension, and viscosity, are evaluated for B100, B5, B10, B20, and B30. Such data are required for input parameters of a spray modelling which is under preparation. The above properties can be used to predict the soray characteristics under typical injection pressure and air density. In this study, only the sauter mean diameter (SMD) is evaluated using semi-empirical formulae from other study. It is found that the SMD for the above biodiesel blend is 24,6 mn, compared to with 20,4 mn for pure biodiesel fuel. The SMD for other compositions are also evaluated up to B30; in which it is found that the SMD is 21,6 mn. The effect of injection pressure is also studied.