PREDICTING THE PHYSICAL PROPERTIES OF BIODIESEL FOR COMBUSTION MODELING

Abstract

As the use of biodiesel becomes more widespread, researchers have shown a strong interest in modeling thecombustion processes in the engine in order to understand the fundamental characteristics of biodiesel combustion. In theearly phase of the simulation, accurate prediction of the physical properties of biodiesel is critical in the representation ofspray, atomization, and combustion events in the combustion chamber. The objective of this article is to present methods forpredicting key physical properties including critical properties, vapor pressure, latent heat of vaporization, density, surfacetension, and liquid viscosity for biodiesel that can be used for combustion modeling. Predicted results were compared withpublished data where available, and for some properties, errors were less than 1%. While no published data were availableat temperatures above 373 K to check the accuracy of the predictions from the models at the higher temperatures, the trendsin the fuel properties were regarded as representative of what would be expected in the combustion chamber. These modelscould be used in a detailed combustion model such as KIVA to make relative comparisons between fuels.