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The ever-increasing cost of automotive powertrain development is due to the more complex technologies required to meet the latest emissions legislation and customer expectations. Manufacturers need to conduct extensive development loops of test bench and on-road testing to verify the hardware, emission control system, corresponding ECU software function development. Increased resources are required to build up a comparably large number of prototype vehicles to calibrate all the ECU algorithms and functionalities. Increasing powertrain complexity leads typically to a strong increase of conventional calibration efforts. Therefore, there is a strongly increasing need for an advanced calibration approach based on multi-facial XiL simulation.

The urea NOx selective catalytic reduction (SCR) is an effective technique for the reduction of NOx emitted from diesel engines. Urea spray quality has significant effect on NOx conversion efficiency. Air less injection is one of effective, less complex way of injecting urea spray into the Exhaust stream. Further with air less injection it become more challenging in an engine platform of ~3 to 4L where Exhaust mass flow and temperature are relatively less. The droplet diameter and velocity distribution of De-Nox system has taken as input along with Engine raw emission data for a numerical model. The atomization and evaporation of airless urea injection systems were modeled using computational fluid dynamics. The numerical model was validated by the experimental results.

Increased options and flexibility in common rail direct injection provides a great opportunity for combustion optimization using fuel and air system with proper combustion chamber configuration. This paper elaborates the experimental work conducted for combustion optimization with combinations of piston bowl, intake port swirl, injector specifications and turbo charging on a 3.8 l four valve diesel engine of LDT application equipped with common rail fuel injection system and waste gate turbo charge. In meeting the target emission norms with internal engine measures, the design of the piston bowl and the nozzle configuration perform a defining role. Through simulations the best option had been carried out parametrically investigate the influence of piston bowl geometry and nozzle characteristics on the performance of the combustion system.

An efficient after treatment technique is driven by the need to maintain strict emission norms for heavy-duty and medium-duty ground vehicles. SCR being an advanced active emission technology system for diesel engine, is one of the most cost-effective and fuel-efficient technologies available for complying with the stringent NOx emission legislations. The design of the SCR system involves catalyst selection, complex controller development like urea dosing strategy and the interaction between engine setup and after treatment system. For this purpose, the SCR model must be computationally efficient to evaluate the complete efficiency along with to take care for the NH3 slip also. The SCR model was prepared with respect to SCR inlet temperature and ratio of NOx and ammonia to study the behavior of NOx conversion efficiency keeping consideration of NH3 slip also required for optimizing the calibration.