o Effect of fuel injection pressure and injection timing on spray characteristics and particulate size–number distribution in a biodiesel fuelled common rail direct injection diesel engine

In this paper, effect of varying fuel injection pressures and injection timings on particulate size number distribution and spray characteristics was investigated in a single cylinder, common rail direct injection (CRDI) compression ignition (CI) engine fueled with Karanja biodiesel blends vis-a-vis baseline mineral diesel. The investigation results of spray tip penetration and spray area of biodiesel blends and diesel showed that higher fuel injection pressure result in a longer spray tip penetration and larger spray area than that at lower injection pressures at same elapsed time after the start of injection (SOI). In order to compare the effect of fuel injection parameters, 10, 20 and 50% Karanja biodiesel blends at 1500rpm engine speed were compared with baseline data from mineral diesel. It was observed that average particulate size increased with retarding the SOI timings. Particulate number concentration was lowest for 10% biodiesel blend, which increased with further increase in biodiesel content in the blended test fuel. Addition of even very small quantity of biodiesel in the test fuel helped in reducing particulate emissions.Research Grant from Department of Science and Technology, Government of India, and Ministry Of Education, Science And Technology, Republic Of Korea under Indo-Korea Joint Program of Cooperation in Science & Technology (Grant Order No. INT/KOREA/P-04 dated 13-09-2011) is gratefully acknowledged, which enabled us to undertake this joint research project. Financial support provided by Council of Scientific and Industrial Research (CSIR), Government of India under Senior Research Associate (Pool Scientist) scheme, which supported Dr. Atul Dhar for conducting this research