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Euro 6 European legislation emission limits, expected to be introduced around the 2014 timeframe, Lean NOx Trap (LNT) Aftertreatment technology is today considered one the of candidate technology to allow diesel Engine to meet the future Euro 6 limit. The working principle of the LNT is based on its capability to store the NOx engine out during the normal lean (excess of Oxygen) phase operation condition of the Diesel engine. The NOx will be then reduced in a dedicated regeneration phase which consist in creating for relatively short time a rich exhaust gas condition inside the LNT. The LNT regeneration strategy lead to run a Diesel engine with a rich mixture out of the combustion as a Gasoline engine. This can be obtained using advanced air and fuel management. The fuel management implicate the use of delayed injections (after and/or post injections) which can have a direct impact on oil dilution.

Race internal combustion engines are the result of several years of design made to satisfy the growing demand of high specific power. As a result of this increased specific power demand all of the engine components that require lubrication are exposed to a broader range of more extreme operating conditions. Hence an optimized design of a race engine lubricant circuit is becoming much more important, due to the necessity to have its effectiveness with a rational management of its own energy. In this paper, Authors analyse a motorbike high performance lubrication circuit by a simulation methodology, already used and validated for other high performance engine types. It will be illustrated a simulation model, made by mono-dimensional (1D) code, which allows to study all lubricant circuit behaviour, analyzing parameters that are not easy to evaluate experimentally and that, too often, designers don't take into account during engine development.

With the increase of specific power, in development of modern engines, also the demand on the cooling system has significantly increased. CFD analysis reveals the occurrence of localized boiling, since often the measured temperature distribution cannot be explained by convective heat transfer alone [1]. The requirement for highest heat transfer rates has led to the very promising concept of a controlled transition from pure convection to subcooled boiling in the critical thermal conditions [2]. However, computational fluid dynamics is still unable to represent boiling flow, while any boiling based strategy requires a right prediction of heat transfer rates on the coolant surface inside IC engines. Chen's heat transfer model for boiling region [1, 2, 4, 6] is widely used today, to predict and compare the predicted heat transfer coefficients in circular and rectangular ducts with experimental results.

During the development of high performance engines attention must be paid to the cooling system design. In fact this plant design, on one hand, should guarantee the thermal power transferred from the engine while, on the other hand, should minimize the car aerodynamic resistance with no excessive crossing sections. In this paper are shown the results of thermo-fluid-dynamic model of an 8 cylinder high-performance engine cooling system, validated by both thermal and hydraulic experimental data. The model validation has been carried out by a dedicated experimental tests with temperature, pressure and flow data acquisition of the cooling system that, generally, are not monitored during the standard experimental data. In particular, this study has been carried out on a simulation of a standard test, called “Punto di Fiorano” where the expansion tank temperature and pressure behaviour have been simulated together with other cooling circuit parameters during an engine heatstroke test.

Lean NOx Trap (LNT) catalysts are capable of reducing exhaust NOx emissions from Diesel engines. NOx is stored on the catalyst substrate during the normal engine operation (lean mixture) and is reduced under rich exhaust condition (rich mixture) during the regeneration event. There are different methods to obtain the rich conditions and one of this is the so called “in cylinder” regeneration. This technique is feasible if the engine is equipped with electronic injection system (i.e. Common Rail system), in fact it is possible to obtain rich Air/Fuel ratios conditions using different injection strategies. Generally, one method to obtain the rich condition for the LNT regeneration consists of additional fuel's injection into the engine cylinders while acting at the same time on EGR and Throttle Valve to reduce the intake air flow.

The modern common rail Diesel engines are normally optimised for being fuelled with the commercial Diesel fuel. Consequently, the ECU calibrations are defined to realize the best compromise between performances and emissions. If the engine is fuelled with an alternative biofuel with different characteristics (net heating value, stoichiometric A/F ratio, density, viscosity, etc.) it is clear that the calibration must be modified. Interest in fuels from renewable sources and their use in transportation has grown over the last decade. This is because of their biodegradability, potential improvements in exhaust emissions and benefits on the virtuous CO2 cycle of the earth. This paper demonstrates that it is possible to optimise emissions and performances of a light duty C.R. Diesel engine fuelled with a vegetable derived fuel (Rapeseed Methyl-Ester) pure or blended with commercial Diesel fuel.

Interest in fuels from renewable sources and their use in transport has grown over the last decade. This is because of their biodegradability, potential improvements in exhaust emissions and benefits on the virtuous CO2 cycle of the earth. Biodiesel fuels can be derived from rapeseed, sunflowers, and other kind of seeds or from UFO (Used Fried Oil). This paper analyses the results of an experimental study fuelling a Common Rail Diesel Engine with a 100% rapeseed Biofuel, with a blend of rapeseed and UFO biodiesel and compares it with commercial diesel fuel Other papers by the same authors compared the different physic-chemical characteristics of biofuels, against diesel fuel and the consequent different spray characteristics that affect the combustion phenomenon. These characteristics are correlated with the different performances and emissions obtained in the experimental activity when a modern Common Rail light duty diesel engine is adopted.

A theoretical-experimental analysis of a VVT engine and a methodology for the definition of its control map is presented. The analyses are based on the employment of a very accurate engine code, developed by the authors, which belongs to the category of the wave propagation models. The code is validated by comparison with experimental data collected on a traditionally fixed- and a variable-valve timing engine as well. The model is also linked to an efficient optimization procedure, which is able to select - for each assigned operating condition - the most appropriate values of control parameters (spark advance, intake/exhaust valve opening/closing, and valve lift), with the objective of pursuing torque or BSFC improvements, idle stability and emission control.

The 1997 Kyoto International Conference Protocol committed industrialized countries to reduce their global emissions of greenhouse gases within the period 2008 2012 by at least 5% with respect to 1990. In view of this and following the European Community directives, the Italian government approved a three-year pilot project to promote the experimental employment of biodiesel. The methyl esters of vegetable oils, known as biodiesel are receiving increasing interest because of their low environmental impact and their potential as an alternative fuel for diesel engines as they would not require any significant modification of existing engines. Consequently, an experimental research program has been developed to evaluate performance and emissions of a Diesel engine fueled with a methyl ester derived from rape seed (Rapeseed Methyl Ester or RME) by changing the composition of the diesel fuel-RME mixture. This program aims to analyze the performance and emissions of a turbocharged D.I.