Effect of In-Cylinder Conditions on Spray Characteristics of Diesel, Biodiesel, and Biodiesel-Ethanol Blended Fuels

Abstract

The analysis result of liquid fuel combustion performance shows that the factors affecting chamber combustion are the vaporization and atomization of liquid fuel. At the same time, the combustion chamber conditions and the property of liquid fuel, in turn, affect the heat transfer process and atomization quality. The present work aims to study the effect of in-cylinder conditions on spray characteristics of diesel, biodiesel, and biodiesel-ethanol blended fuels. Besides, research of the addition of ethanol in biodiesel blends compared with diesel is also discussed in this paper. Meanwhile, for the sake of contrastive analysis, two prediction models are adopted, and the corresponding research is conducted. With the experimental results and theoretical analysis approach, the extent and main influencing factors of droplet vaporization and breakup in the spray process are reached. The liquid-fuel penetration and spray tip penetration all present a decreasing tendency with the increase of in-cylinder pressure and percentage of ethanol in blended fuel, and these parameters are affected slightly by the change of in-cylinder temperature in certain range.