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In cylinder combustion and emission characteristics are dependent on piston bowl geometry design. In-cylinder fuel air mixing and flame front movement are influenced by piston bowl shape and design. These phenomena in turns affect the combustion behavior and the power developed by the diesel engine. In this study piston bowl geometry optimization of a LMD diesel engine is carried out to improve the torque and BSFC output at low end rated operating zones. The optimized bowl geometry is also incorporated in the engine and validated on the test bed. In this work, a commercially available CFD code AVL FIRE is used for combustion simulation and bowl geometry optimization. The validation of in-cylinder combustion simulation of a 2 liter Turbocharged LMD BS-VI diesel engine with base piston bowl geometry is carried out with the available test data.

The automotive industry is gearing up to meet the accelerated emission compliance changes posed by the government. This transition to eco-friendly system would also necessitate an automotive engineer to retain the engine packaging as compact and simple as possible. The packaging layout considered should not be at the expense of deteriorating engine performance. The work started with concept level layout development, with the aim of having simplified system with minimum number of components. The engine on which the work was carried out was 4cylinder 3Liter with OHC configuration A number of layouts were developed which included gear type, belt drive and integrated shaft arrangement for driving FIP. Each of these concepts were brainstormed with its advantages and disadvantages, based on which two concepts were initially proposed for driving FIP system (i) Front Driven FIP (ii) Rear Driven FIP.

Proper suitability of bolt preload is a pre-requisite whenever we go for component design change. In this paper we have considered connecting rod bolt for our analysis, where-in the design pre-requisite was whether same tightening specification could be carried forward from normal to fracture split type. The present work focuses on comparison of bolt design parameters, inertia force, contact pressure & bearing pressure calculation. Bolt safety factor was used as a parameter to check for the preload suitability with respect to engine max permissible speed. A systematic approach, considering guidelines from available bolt standard and literature was used for carrying out related analysis. For improving the quality of judgment, FEA tools along with durability testing was carried out at ARAI. In addition to this for better bolt preload control “Angle tightening method” of required specification was proposed, with results validated through physical testing.