JFET_V5_N4_RP2 A. Gopinath Sukumar Puhan G. Nagarajan Journal on Future Engineering and Technology 2230 – 7184 5 4 19 22 Biodiesel, Density, Regression model, Surface Tension Biodiesel is a name applied to fuels produced by the transesterification of vegetable oils. Biodiesel fuels are generally classified as Fatty Acid Methyl Esters (FAME). As the use of biodiesel becomes more widespread, the researchers have shown a strong interest in modeling the engine combustion processes to understand the basic characteristics of the combustion of biodiesel. Density and surface tension of a fuel are the main contributing factors for the combustion process in a diesel engine. The objective of the present work is to theoretically predict the surface tension of different biodiesel from their density using a regression model. The density and surface tension of different biodiesels were taken from the available published data. A linear regression model was developed to predict the surface tension of different biodiesels and compared with the reported data. The predicted results showed that the error was less than 2% compared to available published data. May - July 2010 Copyright © 2010 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=1266