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Concerns about climate change have significantly accelerated the process of vehicle electrification to improve the sustainability of the transportation sector. Increasing the adoption of electrified vehicles is closely tied to the advancement of reliable energy storage systems, with lithium-ion batteries currently standing as the most widely employed technology. One of the key technical challenges for reliability and durability of battery packs is the ability to accurately predict and control the temperature of the cells and temperature gradient between cells inside the pack. For this reason, accurate models are required to predict and control the cell temperature during driving and charging operations. This work presents a set of procedures tailored to characterize and measure the thermal properties in li-ion cells and modules.

Nowadays, due to catalyst improvements and electronic mixture control of last generation vehicles equipped with internal combustion engine, the most significant part of the total emissions of carbon monoxide and unburned hydrocarbons takes place during the cold phase, if compared with those exhausted in hot conditions, with a clear consequence on air quality of urban contexts. The purpose of this research, developed by the Department of Industrial Engineering of the University of Naples Federico II with reference to an European background, is a deeper analysis of the engine and after-treatment system behaviour within the cold start transient and the evaluation of cold start additional emissions: a methodology was developed and optimized to evaluate the cold transient duration, the emitted quantities during the cold phase and the relevant time-dependence function.

In recent years, in order to optimize performance and exhaust emissions of internal combustion engines, the design of auxiliary systems assumed a particular importance especially due to the need to obtain higher efficiency and reduce power losses required by these components. In this sense, looking at the lubrication circuit, it appears important to use solutions that allow to optimize the fluid dynamics of both the ducts and the pump. In this paper a tridimensional CFD analysis of a lubrication circuit oil pump of a modern high-performance engine will be shown. In this particular application there is a variable displacement pump used to optimize the operative conditions of the lubricant circuit in all engine running conditions. This variable displacement pump changes the positions of the ring as a function of the boundary conditions.

In recent years, the need to optimize the performance and reduce exhaust emissions of internal combustion engines has caused the design of the auxiliary (like lubrication and cooling pumps) to assume a particular importance. This is especially due to the necessity to obtain higher efficiency with less expense in terms of work assigned to these organs. With respect to the lubrication circuit, this means the use of solutions that allow the optimization of the fluid dynamics of both the ducts and the pump. This work is based on a simulated analysis carried out on the lubrication circuit of a light duty internal combustion engine, developed by Fiat and equipped with a hydraulic VVT system.

The aim of this study is to investigate the effect of ethanol-gasoline mixtures on cold emissive behavior of commercial motorcycles. For the newly sold motorcycles, equipped with a three-way catalyst and electronic mixture control, CO and HC cold additional emissions, if compared with those exhausted in hot conditions, represent an important proportion of total emissions. On the other hand, ethanol is known as potential alcohol alternative fuel for spark ignition engines, which can be blended with gasoline to increase oxygen content and then to decrease emissions. From this explanations, a research on cold start emissions of motorcycles using ethanol-gasoline mixtures was conducted.

The aim of this paper is the analysis of a Diesel engine lubrication circuit with a tri-dimensional CFD technique. The simulation model was built using Pumplinx®, a commercial code by Simerics Inc.®, developed and optimized for predicting oil flow rates and cavitation phenomena. The aim of this paper is, also, to show that this code is able to satisfactorily model, in a very “economic” way, an unsteady hydraulic system such as the lubrication circuit First of all, an accurate model of a lubrication circuit oil pump will be described. The model was validated with data from an experimental campaign carried out in the hydraulic laboratory of the Industrial Engineering Department of the University of Naples. Secondly, the oil pump model was coupled with a tri-dimensional model of the entire lubrication circuit, in order to compute all the hydraulic resistances of the network and the oil consumption rate of the circuit components

This paper is based on a Research Project of the Department of Mechanical Engineering (DiME) in collaboration with Aprilia, the Italian motorbike manufacturer. In an attempt to simulate the functioning of the cooling plant of the Aprilia RSV-4 motorbike a numerical model was constructed using mono-dimensional and three-dimensional simulation codes. Our ultimate aim was to create a simulation model which could be of assistance to engine designers to improve cooling plant performance, thereby reducing research and development costs. The model allows to simulate the running conditions of the whole cooling circuit upon variations in environmental and running conditions. In particular, the centrifugal pump of the cooling plant was simulated by a 3D commercial software, while the whole circuit was built by a 1D commercial code which allows simulation of all the thermal exchanges and pressure drops in the cooling circuit.

In all the world mopeds and motorcycles are popular means of daily moving, helping to meet daily urban transport needs, as a consequence two-wheelers contribution to air pollution is generally significant, especially in urban environment. Emission models commonly used in Europe, are based mainly on the average trip speed to predict emissions, thus they are not sensitive to variations of vehicles instantaneous speed and acceleration, which have a strong effect on emissions and fuel consumption; besides these models do not analyze in depth the cold emissive behavior of motorcycles. An expansion of the two-wheelers emission database was deemed necessary. This study is aimed at the examination of the emissions of in-use motorcycles during real driving conditions, contributing significantly to extend the knowledge of two-wheeler emission behavior.

All the experimental investigations performed in the last years on newly sold motorcycles, equipped with a three-way catalyst and electronic mixture control, clearly indicate that CO and HC cold additional emissions, if compared with those exhausted in hot conditions, represent an important proportion of total emissions. Consequently, calculation programs for estimating emissions from road transports for air quality modeling in dedicated local areas should take into consideration this effect. From this motivation, an experimental activity on motorcycles cold emissive behavior is being jointly conducted by Istituto Motori of the National Research Council (IM-CNR) and the Department of Mechanic and Energetic (DiME) of the University of Naples.

In the last ten year the mechanical power output of car engine increased significantly. This result has been possible especially through new injection systems that brought to an optimization of the combustion (direct injection, common rail) and to an improvement of the turbocharging. Moreover, these technical devices brought a reduction of the exhaust emissions and an increasing of the engine efficiency. In particular, the specific power is increased from 34 kW/liter of 1992 to the 63 kW/liter of 2010. Furthermore, the pressure peaks into the combustion chamber and the fuel injection pressure have been increased to the aim of emission reduction and higher engine efficiency. In this scenario, car manufacturers are following the direction of the engine downsizing that means to have the same engine power by a lower engine displacement.

Mopeds are popular means of transportation, particularly in southern Europe and in eastern and southern Asia. The relative importance of their emissions increases in urban environments which host large fleets of mopeds. In Naples, for example, mopeds make a considerable contribution to HC emissions (about 53%), although the percentage of mopeds (12.4%) in the total circulating fleet is lower than that of other vehicle categories [1]. This study presents a method for analysing the influence of kinematic parameters on the emission factors of mopeds during the “cold-start” and “hot” phases of elementary kinematic sequences (speed-time profiles between two successive stops). These elementary sequences were obtained through appropriate fragmentation of complex urban driving cycles. In a second step, we show how to estimate, for the whole cycle, the duration of the cold phase and the relevant time-dependence function.

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.

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.

A wide experimental investigation on a 16 valves, 1242 cm3 SI-engine is reported. Experimental data were collected in correspondence with about 250 different operating conditions of the engine. This allowed to deeply assess the accuracy of a simulation model (1Dime code), developed by the authors, based on a one-dimensional computation of the gas flow in the manifolds, and on a quasi-dimensional fractal approach for combustion simulation. The model is then employed to theoretically verify the advantages that can be exploited from the adoption of various VVT (Variable Valve Timing) or VVA (Variable Valve Actuation) systems, including those realizing a throttle-less operation of the engine. The gains predicted in terms of torque profile at WOT, and of BSFC or NOx emissions at part load are quantified and discussed.

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.

As U.S. and European regulation of automotive emissions is getting more stringent, great interest is growing around new solutions for future emission standards. Pollutant reduction can be achieved improving both engine out emission and aftertreatment system efficiency. Engine out emission can be reduced improving combustion process especially during warm-up, friction and the engine management system. In any case engine out emission reduction involves engine sophistication increasing costs, which must be accurately evaluated, especially for small displacement large mass production engine. Since, as it is well known, 80 - 90 per cent of HC and CO emissions are produced during the first 100s of NEDC cycle, great improvement could be achieved reducing the catalyst light-off time. Different configurations of exhaust gas after treatment system have been tested to improve conversion efficiency during warm-up phases.