Temperature dependence viscosity and density of different biodiesel blends

Abstract

The main goal of this paper is to assess the effect of rapeseed oil methyl ester (RME) concentration in diesel fuel on its viscosity and density behaviour. The density and dynamic viscosity were observed at various mixing ratios of RME and diesel fuel. All measurements were performed at constant temperature of 40 °C. Increasing ratio of RME in diesel fuel was reflected in increased density value and dynamic viscosity of the blend. In case of pure RME, pure diesel fuel, and a blend of both (B30), temperature dependence of dynamic viscosity and density was examined. Temperature range in the experiment was -10 °C to 80 °C. Considerable temperature dependence of dynamic viscosity and density was found and demonstrated for all three samples. This finding is in accordance with theoretical assumptions and reference data. Mathematical models were developed and tested. Temperature dependence of dynamic viscosity was modeled using a polynomial 3 rd polynomial degree. Correlation coefficients R -0.796, -0.948, and -0.974 between measured and calculated values were found. Temperature dependence of density was modeled using a 2 nd polynomial degree. Correlation coefficients R -0.994, -0.979, and -0.976 between measured and calculated values were acquired. The proposed models can be used for flow behaviour prediction of RME, diesel fuel, and their blends.