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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.

Worldwide IC engine fuels are increasingly blended with oxygenate fuels to reduce the dependency on the conventional petroleum reserves. Among these fuels, biomass-derived ethanol is very popular for SI engine operation as it is not only economical and renewable source of energy, but it also allows increasing the engine performance. High latent heat of vaporization of ethanol combined with its high octane number make the engine less sensitive to knock. However, the real potential of ethanol blended fuels still has to be explored and their impact on engine combustion characterization has to be investigated. The objective of this study is to extend predictive fractal combustion model for ethanol/gasoline blends and assess the influence of ethanol addition to gasoline in a Port Fuel Injection (PFI) engine. Quasi dimensional simulation is carried out using AVL Boost under wide open throttle condition at 1500 and 3000 rpm.

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.