Numerical expressions for viscosity, surface tension and density of biodiesel: analysis and experimental validation

The purpose of this work was to test the accuracy and predictive power of different numerical methods in order to compute reliable values of viscosity, surface tension and density of biodiesel in a wide range of temperature. Available formulae in literature were used to compute the mentioned properties in the temperature ranges in which they were developed. To validate the numerical expressions we have used experimental measurements of viscosity, surface tension and density performed in our laboratory and published in the literature. In this article, the results obtained by the application of different expressions are shown and possible sources of discrepancy between measured and predicted values are mentioned. The method that predicts the best results is identified for each property. In order to achieve a better fitting to the experimental data, corrections in the expression of the temperature-dependent properties were made when they were necessary.

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