Mathematical modelling of evaporation rate and heating of biodiesel blends of a single-component droplets

Abstract

Biodiesel serve as promising fuel and optimal alternative for mitigating the present issues of fuel scarcity and emission control in compression ignition engines. Several Researches have concluded that engine performance and it’s emission characteristics heavily depends on pa-rameters like fuel droplet spray formation, atomization, evaporation and combustion which in turn depend on thermophysical properties of biodiesel fuel. In this study, the thermophysical properties like normal boiling, critical properties, vapor pressure, latent heat of vaporization, liquid density, liquid viscosity, liquid thermal conductivity, gas diffusion coefficients of two biodiesel fuels sample: Madhuca Indica and Radish oil are determined using standard correla-tion. Accurate mathematical model for estimation of evaporation rate and combustion of sin-gle component biodiesel droplet is framed and validated with single droplet setup experiment result for Jatropa Methyl Ester (JME), Karanjan Methyl Ester (KME), Mahua Methyl Ester (MME), Neem Methyl Ester (NME), Palm Methyl Ester (PME) oil and this model is further extrapolated to predict the evaporation and combustion behaviour of two unexperimented oil, Madhuca and Radish. It is found that Madhuca oil has the higher evaporation constant value of 0.1466 mm2/s and thus lowest lifetime in among the biodiesel fuel studied. This value is attributed to lower mo-lecular weight and higher molecular diffusivity. On the other hand reverse trend is observed in Radish with lower evaporation constant and higher lifetime. This study behaves as compre-hensive methodology for estimating the behaviour of biodiesel based on their composition and chemical structure and also as firm framework for combustion modelling in enhancing engine performance.