Predicting the Temperature and Composition – Dependent Density and Viscosity of Diesel Fuel – Ethanol Blends

Abstract

Density and viscosity are very important fuel properties which have a major influence not only on the fuel production, transportation and distribution processes but also on the processes that take place in an internal combustion engine. Developing robust and high precision density and viscosity models for stabilized diesel fuel – ethanol blends helps the production of fuel to adhere to the quality requirements regarding density and viscosity and the modeling and simulation of injection and combustion processes. For modeling the density and the viscosity of diesel fuel – ethanol blends, five mixtures were prepared with ethanol content up to 15 % (v/v) and were stabilized by adding tetrahydrofuran as a surfactant at room temperature. The temperature-dependent density and viscosity of the blends were measured at four different temperatures (0, 15, 40 and 50 °C) using an SVM 3000 type apparatus. Based on experimental data, several mixing rules were fitted to them and three new models were developed, of which two need only one experimental value. These models yield very good accuracies, presenting average relative deviations of 0.0604 % in the case of density and 3.8931 % in the case of viscosity.