The present work focuses on optimization of biodiesel combustion phenomena through parametric approach using response surface methodology. Physical properties of biodiesel play a vital role for accurate simulations of the fuel spray, atomization, combustion, and emission formation processes. Typically methyl based biodiesel consists of five main types of esters: methyl palmitate, methyl oleate, methyl stearate, methyl linoleate, and methyl linolenate in its composition. Based on the amount of methyl esters present the properties of pongamia bio-diesel and its blends were estimated. CONVERGETM computational fluid dynamics software was used to simulate the fuel spray, turbulence and combustion phenomena. The simulation responses such as indicated specific fuel consumption, NOx, and soot were analyzed using design of experiments. Regression equations were developed for each of these responses. The optimum parameters were found out to be compression ratio ? 16.75, start of injection ? 21.9? before top dead center, and exhaust gas re-circulation ? 10.94%. Results have been compared with baseline case.

Multiple injection strategy is a vital strategy to reduce the soot and NO_x emissions concurrently. The multiple injection strategy can enhance the air/fuel mixture, combustion and exhaust emission characteristics by providing a small amount of fuel before the main injection. Among all types of alternate fuels, biodiesel has emerged as an eco-friendly fuel for the diesel engines. This paper is focusing on the effect of pilot injection strategies on diesel engine say timing (−30° bTDC to −50° bTDC) and by varying the fuel quantity (5–15%). The performance, combustion and emission characteristics of Palm-munja biodiesel/diesel blend (B20) were investigated on CRDI diesel engine. The experimentations were carried out on a constant speed by varying loads from 0 to 100%. The experimental results show that as an increase in pilot injection timing there is a reduction in the in-cylinder pressure, whereas soot and NO_x emissions decrease as the pilot injection timing increases. As the pilot injection fuel quantity increases, the in-cylinder pressure and NO_x emission increase, whereas soot emission decreases.

As major limitation of diesel engines is the high soot and nitrogen oxide emissions which cannot be reduced totally with only conventional catalytic converters today, varying fuel characteristics became a focus of interest to meet the pollution emission legislations as they require very few or no changes in existing engine model. The present work deals with, numerical analysis of combined effect of Advanced Start of Injection (SOI) and Exhaust Gas Re-circulation (EGR) on performance and emissions which were studied, by performing numerical analysis on a Caterpillar 3401 single cylinder C.I engine model at constant speed using diesel as fuel via three dimensional computational fluid dynamics (CFD) procedures and validated with experimental data. The SOI is advanced from 11° Crank angle bTDC to 14.5° Crank angle bTDC and EGR as a fraction is increased from 0% to 10%. The modified conditions of these parameters resulted in simultaneous reduction of NOx and Soot