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This paper is focused on the prediction of in-cylinder pressure, temperatures and engine-out NOx. One of the important factors influencing engine output parameters is the rate of heat release, which affects the in-cylinder pressure, temperature and engine out emissions. A single-zone model is formulated for prediction of heat release and in-cylinder pressure. Being a predictive model, this model does not required cylinder pressure as an input. Combustion pressure is predicted by modeling compression pressure, ignition delay, heat release, and heat loss. Required Sub-models have been obtained from the literatures. Fuel burning rate is predicted using Watson model. To retain the computational efficiency and better prediction accuracy a two-zone model has been formulated to predict NOx emissions. Flame temperatures are predicted by enthalpy balance. Thermal NO concentration is predicted by using basic Zeldovich mechanism.

Environmental pollution is of great concern; hence the emission norms for the diesel engines are made more stringent. The purpose of this work is to develop a process to optimize the FIS parameters and select a most suitable FIS by simulation to meet the target emissions. During the combustion optimization exercise of diesel engine, different hardware combinations like injector, HPP etc are matched through testing to achieve the required performance and emissions. The process requires the real testing of the engine on engine dynamometer with various hardware combinations, which is expensive and time consuming. A simulation model of diesel FIS is constructed using ‘AVL Hydsim’. The model is validated by comparing the predicted and the experimental results. The validated model is used for further work. Critical parameters were listed based on the sensitivity analysis on the base model.

To meet the latest trends in internal combustion engines pertaining efficiency, emissions and durability, downsizing of the engine has become the key focus area. This paper describes about a robust, reliable and an integrated approach used in design and development of state of art high power density/ high speed engine developed from the concept, which can be adopted for passenger car and LCV application. A three-cylinder, 1.5 liter displacement diesel engine, fully balanced is being designed with an objective to produce 115kW @ 4200 rpm, delivering a specific power output over 75 kW/liter, which is at par with a contemporary class of specification in it. In the first stage, a derated version of 75 kW (50 kW/liter) with Euro-IV and Euro-V specifications is targeted aiming at smaller car and light motor vehicle segment and a prime-mover for hybrid application.

Development, optimization and calibration of diesel engine parameters have become extremely complex, because the recent technology engines have too many parameters and their interactions, which play significant role in controlling emissions. To reduce development time and cost, a systems approach to engine optimization is possible through an effective Design of Experiment (DoE). Various steps were devised like setting measurable target quantity & customer demands, parameter evaluation & screening, fractional factorial - orthogonal array design, experimentation, evolving objective/merit function, analysis, determination of optimum combinations and success run for validation. A naturally aspirated DI diesel engine is optimized using DoE for optimum performance and minimum emissions.