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In this work, the ignitjion delay of bio-diesel and its blends with diesel at atmospheric pressure and temperature 8500C has been studied. The results are compared to those for diesel oil. Specifically, the suspended fuel droplet is inserted into a hot combustion chamber containing atmospheric air at temperatures which varied from 6250 - 8500C. The fuel droplet is suspended on the fine silica fibre wire of diameter 550 micron. It is mounted on rod and inserted in the hot combustion chamber at atmospheric condition. The ignition of the droplet is observed by optical circuit (optical sensor) and recorded by CRO. The ignition time is determined for calculating ignition delay. The results are plotted on the ignition delay ln(t) - 1/Temperature, K-1 coordinates to obtain the value of Activation Energy, EA. It has been found that the value of Activation Energy, EA is 44.3kJ for bio-diesel and 53.4kJ for diesel.

It is easy to identify flow induced noise on a flow bench or engine testing, but it is also equally essential to understand the fundamental mechanisms of fan noise generations. A methodology for optimizing cooling fan noise using 3-D CFD technique is presented in this paper. This work is an extension of Reference Nain, A. [2], where cooling fan dimensions like blade shape, number of blades, blade diameter etc. are optimized for achieving fuel efficiency targets. Any design modification in a fan should also be validated for any cause of noise generation. Initially engine noise sources are identified experimentally in anechoic chamber. Each noise source is categorized in order of their dominance on overall noise level. The cooling fan system impact is also extracted from overall noise spectrum.

EGR flow within individual cylinder as per requirement has a great importance which controls the performance and emissions of the diesel engine. The work presented here, elaborates the mixing process of EGR in the manifold with the fresh charge entering into intake manifold and then into cylinder. The study is carried on our three-cylinder diesel engine. For the simulation of such highly pulsating flow, the boundary conditions were generated from 1D model & in the back end the 3D CFD is used to solve the EGR mixing in a transient phase. The mixing at each cylinder port is evaluated using the Air and CO2 mass fraction at outlet of each intake port. Being a transient nature of valve operation, the EGR distribution within the manifold observed stabilized in 9 cycles. It was observed that the flow pulsations at the EGR inlet have large influence on the EGR distribution.

The paper presents the investigation on the Engine fuel efficiency improvement using one-dimensional (1-D) simulation software Ricardo WAVE. The study is carried out for a baseline multicylinder direct-injection turbocharged diesel engine of 2945 cc displacement, meeting the Central Pollution Control Board (CPCB)-II emission norms. Initially, the base simulation model is calibrated and observed for a good correlation between the experimental and simulation results for parameters like airflow rate, engine power, brake-specific fuel consumption (BSFC), and cylinder pressure. There is also an acceptable agreement between the predicted and actual measurement values for nitrogen oxides (NOx) emission. Now different combinations of turbochargers and combustion-related hardware are optimized in 1-D simulation, and the best combination is also verified experimentally.