<b>Modeling of Biodiesel Fuelled Direct Injection CI Engine using CFD</b> In present years, biodiesel is used as a fuel in internal combustion engine. This study deals with the combustion modeling of CI engine fuelled with Karanja oil as biodiesel. Combustion characteristics like heat release rate, cylinder pressure and rate of pressure rise have been analyzed. CFD code Fluent is used to model complex combustion phenomenon in compression ignition engine. The sub model like k e model, Taylor Analogy breakup model and droplet collision model are used. For modeling of in cylinder combustion, finite rate chemistry and species transport models are used with simplified chemistry reactions. The modeling results were compared with the experimental results. The simulated combustion results are found satisfactory with the experimental results. The major objective of this paper is to study how combustion phenomenon occurred in engine cylinder with the help of CFD and also to understand the effect of biodiesel on CI engine combustion. Combustion characteristics, Biodiesel, CFD modeling, simulation 391-394 Issue-6 Volume-1 Maulesh H Parikh | Mori Nirav B