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The present work is concerned with the computation of in-cylinder flow field of a naturally aspirated single cylinder diesel engine using 3D CFD methods. Flow in the intake port and across the valve and subsequent in-cylinder flow is simulated for different valve lift conditions. The in-cylinder flow field is thoroughly analyzed for the flow asymmetry, number of vortices and swirling motion. Predicted velocity field at 20 mm and 92 mm sections from the cylinder head is compared with those obtained from the experiments. Doppler global velocimetry has been used to measure the velocity vectors at the two earlier identified sections for vale lifts of 2, 4, 6, 8 and 9 mm. The development of flow in the longitudinal and transverse directions is studied from the measured velocity vectors. The evolution of the global in-cylinder flow structure with respect to the lift is presented.

One of the major challenges for automotive industry today is to reduce tailpipe emission without compromising on fuel economy especially with the EURO 6, RDE, LEV III emissions and CO2 norms coming up. In case of diesel engines, with the emission norms becoming stringent more and more, it's difficult to improve tradeoff between NOx and PM emissions. After treatment systems give some edge in terms of tail pipe emission reduction but not on the cost, fuel economy and system simplicity front. For diesel engines the compression ratio and design of the bowl geometry plays a crucial role in controlling emission and CO2. The target was to achieve EURO 6 tailpipe emissions with minimum dependency on after treatment. With the target after treatment conversion efficiency the engine out targets were framed. A study of different bowl geometries were made that would help achieve this target of improving reduced engine out emissions.

In this paper, Authors tried to investigate the influence of Low Temperature EGR (LtEGR) on NOx, PM emissions and fuel efficiency in NEDC 120 cycle. Sports Utility Vehicle (SUV) less than 3.5T vehicle selected for investigation of LtEGR. The existing water cooling circuit modified to suitable to handle the LtEGR concept without changing the existing EGR cooler. Cooled EGR technology has two benefits in terms of handling high EGR ratios and more fresh air within the engine displacement. Under this assumption separate LtEGR layout was prepared for the evolution of superior EGR cooling technologies and low pressure EGR.