Combustion Optimization of Biodiesel for Diesel Engines with the Aid of KIVA-3 Code

Biodiesels are considered to be potential extenders or substitutes for crude oil-derived diesel fuel. Research has shown that these fuels can be used successfully in unmodified engines. Results of preliminary engine tests also show that there is potential to optimize the engine to take advantage of the altered fuel combustion characteristics caused by biofuels. In this study, the physical and thermo-dynamic properties of different blends of biodiesel with no.2 diesel were predicted. The three-dimensional CFD (computational fluid dynamics) code KIVA-3Vrel2 was employed for the computations of performance of both biodiesel and no.2 diesel. The parameters of injection timing, injection duration and EGR (Exhaust Gas Re-circulation) were varied to optimize the performance of an International 7.3 L direct-injection diesel engine. The optimized result shows that shorter duration of injection and more injection advance with EGR rate of 20% is needed to achieve higher fuel efficiency and lower NOx emission for biodiesel.