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Novel port dual-injection (PDI) strategy helps to utilize bio-fuels, improve the performance and lower the emissions with higher mass fractions of bio-fuels. PDI strategy in SI engine allows intake manifold blending of two different fuels at any blend ratio. This paper presents the numerical study of PDI strategy using a single cylinder SI Ricardo E6 research engine. The objective of this study is to extend predictive fractal combustion model for ethanol/gasoline blends and assess the influence of ethanol (E10 to E50 mass fractions) addition to gasoline in a PDI engine. Quasi dimensional simulation is carried out using AVL Boost under wide open throttle condition at 1500 rpm. AVL Boost engine model is validated for gasoline and ethanol/gasoline pre-blends port fuel injection (PFI) with the experimental data of published literature obtained for the same engine.

Use of microprocessor-based controllers in place of traditional governor-based controllers for diesel engines is motivated by the requirement of meeting the increasingly stringent legislations on exhaust emissions and fuel economy. Such controllers can also give improved transient performance. In this paper a fourth order nonlinear mean value model of a 600 HP turbocharged diesel engine is developed for the controller design. Differential equations for various subsystems have been derived using first principles, experimental data and characteristic maps. The model is implemented in MATLAB™ and Simulink™ environment for simulation and controller design. The model is generic and can be modified with a little effort for other heavy-duty turbocharged diesel engines. The nonlinear model is linearized at sixteen operating points covering wide operating range. These models are reduced to second and first order models using a balanced realization.

Engine in-cylinder flow structure governs the combustion process and directly influences emission formation and fuel consumption at the source. In naturally aspirated DI diesel engine, combustion process coupled with low pressure mechanical fuel injection systems set different requirements for inlet port performance. In-cylinder swirl needs to be optimized for efficient combustion to meet emission levels and fuel consumption targets. Thus, intake port design optimization process becomes a vital requirement. In the present paper intake port design optimization is carried out for single cylinder naturally aspirated engine using mechanical fuel injection systems. The objective is to investigate in-cylinder flow field developed by intake port designs, study the effects of geometrical details of various port cross sections on flow velocity and pressure fields and establish a relationship with intake port performance parameters i.e. swirl and flow coefficient.

Future emission limits for off-highway application engines need advanced power train solutions to meet stringent emissions legislation, whilst meeting customer requirements and minimizing engineering costs. DI diesel engines with four valves per cylinder are widely used in off- highway applications because of the fundamental advantages of higher volumetric efficiency, lower pumping loss, symmetric fuel spray & distribution in combination with the symmetric air motion which can give nearly optimal mixture formation and combustion process. As a result, the fuel consumption, smoke levels and exhaust emissions can be considerably reduced. In particular, the four-valve technology, coupled with mechanical low pressure and electronic high pressure fuel delivery systems set different requirements for inlet port performance. In the present paper four valve intake port design strategies are analysed for off highway engine using mechanical fuel injection systems.