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Simulation tools are currently extensively used to assist diesel engine development because they contribute to significant reduction of development cost and time. Given that currently the majority of DI diesel engines are turbocharged it is of vital importance the knowledge of Turbine and Compressor maps for successful prediction of engine performance. This data is often not available from T/C manufacturers, especially for the turbine. However, even if turbine maps are available, efficiency and mass flow characteristics span over a limited range of pressure ratio, due to limitations of conventional T/C test benches. Use of sophisticated T/C test bench equipment that allows measurements at a wider range of T/C pressure ratios results in increased hardware and labour cost. An alternative solution is the development of physically based models for the turbine and the compressor.

A major challenge in the development of future heavy-duty diesel engines is the reduction of NOx and particulate emissions with minimum penalties in fuel consumption. The further decrease of emission limits (i.e., EPA 2007-2010, Euro 5 and Japan 05) requires new, advanced approaches. The injection system of DI diesel engines has an important role regarding the fulfillment of demands for low pollutant emissions and high engine efficiency. One of the injection system parameters affecting fuel spray characteristics, fuel-air mixing and consequently, combustion and pollutant formation is the geometry of the nozzle hole. A detailed experimental investigation was conducted at UPV-CMT using three different nozzle hole types: a standard, a convergent and a divergent one to discern the effect of nozzle hole conical shape on engine performance and emissions.

The fuel injection system of diesel engines is of great importance since it controls the combustion mechanism. The rate of injection and the speed of injected fuel are important parameters for engine operation, controlling the combustion and pollutants formation mechanisms. A fuel injection system simulation capable of predicting the performance of the injection system to a good degree of accuracy has been developed. The simulation is based on a detailed geometrical description of the injection system and in modeling each subsystem as a separate control volume. The simulation starts at the driving mechanism of the fuel pump and describes all parts of the system pump chamber, delivery valve, delivery chamber, connecting pipe and injector. The components of the system are put together and interact as they do in reality. From the cam geometry an analytical expression is derived that gives the pump piston lift as a function of the engine crank angle.