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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.

With the implementation of stringent PM emission norms in various countries for diesel vehicles, the legislation demands a PM mass limit as low as 4.5mg/km in the NEDC cycle, starting from Euro5. This makes the usage of Diesel Particulate Filters (DPF) mandatory. The same is going to be mandated for upcoming BSV emission norms in India. Thus it becomes imperative to know the functional aspects of a DPF and their impacts. Basically there are two major functions of a DPF- Soot mass filtration and Soot burning or Regeneration. This paper highlights usage of DPF in Indian context from the perspective of one of the major aspects of DPF regeneration-Regeneration Interval, which is basically governed by vehicle/engine out smoke. Regeneration interval also has direct or indirect influence on life of engine of a vehicle and average fuel economy of a vehicle which will also be touched upon herein.

In the present scenario, when the vehicle is maneuvering in the gradient, more clutch and accelerator pedal modulations is needed during stop and go condition. These kinds of pedal modulations are not desirable for many customers as it requires more skilled driving. Failure of doing such actions will even result in engine stalling which becomes an annoyance to such customers. In order to overcome this problem, the low idle speed of the engine can be increased only during the drive-off condition. In this paper, we proposed the development and real-time testing of the control algorithm to increase the engine low idle speed during drive-off. This proposed algorithm detects the drive-off condition and then an offset value is added to increase the low idle speed. Various input conditions are considered to enable or disable the increment of engine low idle speed. The control algorithm has been developed using MATLAB/Simulink tool and tested using ETAS EHOOKS tool.

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.

Direct injection diesel engine offers better Performance and fuel economy benefit over gasoline engine. Use of performance prediction software helps to reduce engine emission development time, effort and cost of development. In the present paper, 2.2 Liter, 4 cylinder diesel engine was upgraded for 25% higher power, 18% higher torque and emission from Euro3 to Euro4. Base engine performance prediction was done using AVL Boost software. This Model was validated by base engine performance test results. Boost model was used for parametric study to predict target engine performance. Vehicle simulation model was built with use of AVL Cruise software and run with NEDC test cycle. 14 mode steady state speed-load points of engine were obtained with from NEDC cycle with time weightage factor. Engine hardware like turbocharger, injector, piston cavity, EGR cooler and pilot injection strategy were used for engine power and emission optimization on engine test bed.

High speed diesel engines are difficult to start in cold conditions (at subzero temperature) because the cylinder head and cylinder block absorbs heat of compression and thus preventing ignition due to the high surface to volume ratio. Also the coolant and the engine oil become viscous at subzero temperature and make the condition unfavorable for starting. Combustion optimization along with the help of a heating aid can make these engines to start quickly without any engine misbehavior. Cold startability is the ability of an engine to start within a specified time and continue to run without any malfunctioning. Combustion instability will lead to the misfiring of the engine unless it is calibrated properly. The European countries are subjected to a minimum temperature of -20°C to -25°C. So the intention of this work is to optimize the cold startability of Mahindra's Multi-Purpose Vehicle (MPV) up to -25°C which is to be sold in European countries.

As the emission targets are getting tighter, efforts are made to improve the emission by all possible means. This work emphasis the potential of intercooler to reduce exhaust gas emissions (CO, HC, NOx and PM). A detailed analysis of experimental results on emissions is presented. The effect of intercooler efficiency on emissions is explained. A multi-utility vehicle equipped with common rail diesel engine was tested in NEDC cycle in chassis dynamometer. Ideally the vehicle emission lab should replicate a flat straight road condition & natural airflow. To obtain the airflow a variable velocity fan is used. The velocity of air emerging from the fan and relative position of the fan with vehicle has a significant role in intercooler efficiency and hence on emissions. This work explains the exercise carried out to correlate the intercooler efficiency and exhaust emissions with fan position and velocity.