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This study describes the results of transient behavior for a six-cylinders four-stroke turbocharged diesel engine during the change in operating conditions of the engine by using the computer simulation with measurements on test bed. In order to obtain the dynamic behaviors of the engine, the transient simulation are conducted with serveral kinds of inertia moment ratio in turbocharger and engine, a rapid large load application to the engine, and changes of governor gain constant. From the results of this study, the following conclusions may be summarized. Turbocharger lag is the main cause of the inferior transient performances of turbochared diesel engines. A reduction in the turbocharger moment ratio of inertia brings about the improvement of acceleration performance of disel engines. An increase of the engine moment ratio of inertia decreases cyclic variations of the engine speed.

The combustion characteristics of a diesel engine were examined by means of cyclic variation of combustion pressure and heat release history. In this paper the gas pressure, the rate of pressure rise, heat release rate and the other combustion characteristics of direct injection type diesel engine are investigated for the various pressure crank angle history using a combustion analyzing apparatus. Statistical analysis of combustion characteristics of diesel engine have been carried out over a various range of speed, fuel injection timing, and the several factors using a combustion data of five hundreds cycles of combustion analyzer. The results of this investigation show that the variations of combustion characteristics does change as cycle conditions are altered. The influences of cyclic parameter and operational factors on the combustion characteristics of engine are discussed also.

The objective of this work was to experimentally determine the effect of premixed fuel on the reduction of exhaust emissions in diesel engine. In order to investigate the effect of premixed ratio on the NOx and smoke in a diesel engine, the reduction effect of exhaust emissions of diesel engine is investigated by means of experimental method. In this work, a direct injection type diesel engine with M-combustion chamber modified by using the supply system of premixed fuel into the intake manifold. The experimental apparatus consist of premixed fuel system, diesel injection system and electronic control system. The injection amount of premixed fuel in the intake port controlled by electronic injection system. The results of this study show that the increase of premixed ratio of supplied fuel reduce the nitrogen oxide and smoke emissions of the engine.

This paper describes the effects of two stage combustion strategy on the engine performance and the exhaust emission characteristics in a compression ignition engine. The two-stage combustion strategy targets reduction of NOx emissions by decreasing oxygen concentration for second stage combustion. Thus, the first injection was provided in order to consume in-cylinder oxygen, rather than generate power. A multi-dimensional CFD code was utilized to predict engine performance and emission characteristics. For the accurate and efficient computational calculation of ignition and combustion characteristics of diesel fuel, the reduced n-heptane mechanism was used in this study. The calculation for two-stage combustion was performed after validating against the experimental result. The KH-RT breakup model and gas-jet model was applied for the prediction of spray behavior and characteristics. To calculate the ignition and combustion process, CHEMKIN II [1] code was used.