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The continuous increase of pollutants and fine particulates is mainly caused by cars circulating worldwide. Therefore, it is necessary to replace internal combustion engines with the cleanest electric motors. The short term solution is represented by Hybrid Electric Vehicles (HEVs) due to its environmental and efficiency characteristics. In the present paper a dynamic feed-forward mathematical model for a hybrid vehicle performance analysis is proposed. Torque and power, pollutant emission, fuel consumption, battery pack state of charge, as well as speed and acceleration have been evaluated by means of simulation of United State and Japanese standard driving cycles. In order to carry out simulations on a real hybrid configuration, the model has been based on the powertrain installed on the Toyota Prius (Toyota Hybrid System - THS). A mathematical sub-model of each vehicle component has been implemented to simulate the real vehicle behavior in all possible running conditions.

One of the most important challenges in the design of a hybrid vehicle is the choice of the best control strategy for energy management. This work analyzes and discusses five different rules-based strategies. The authors' main targets were to understand how each strategy acts on the power split and how the operation points of both the Internal Combustion Engine and Electric Motor vary on efficiency maps. So, a critical review was produced of the strengths and weakness of different strategies found in scientific literature and out of it grew two new control plans.

The automotive industry needs a substantial revolution. It is necessary to replace conventional vehicles, equipped with highly polluting and very inefficient Internal Combustion Engines (if compared with the high efficiency of Electrical Motors), with clean, efficient electric vehicles (Zero Emission Vehicles). The electrical vehicles do not produce pollution and are characterized by high efficiency values (about 0.8) respect to ICE (about 0.27). In the transition from vehicles equipped with only ICE, to purely electrical vehicles, a fundamental step is represented by HEVs (Hybrid Electric Vehicles). This paper shows the development, the validation and the use of a numerical code for hybrid vehicle simulation. A quasi-static “backward” simulation code was developed and implemented for an ISA (Integrated Starter Alternator) configuration vehicle. The Willans line approach was implemented to create the HEV model.

In the current work, a heat release model, based on the First Law of the Thermodynamics, has been implemented using a genetic approach. Using this approach, the evaluation procedure of the calibration's constants becomes automatic and accurate. The more accurate is the evaluation of the calibration's constants, the more precise will be the calculation of the heat exchange between charge and cylinder walls, the evaluation of the gross heat release inside internal combustion engines, the evaluation of the rate of heat release, the mass fraction burned, as well as the combustion efficiency.

In this paper, the authors have investigated a new neural network application for the determination of thermodynamic properties for various gases for internal combustion engines applications. The Neural Network has been trained using experimental data available in literature (specific heat at constant pressure, enthalpy, entropy and equilibrium constants for thirteen gases of practical interest inside ICE applications). In the present study a two-layer Elman network feedback from the first-layer output to the first layer input as well as “tansig” neurons in its hidden and out layers has been implemented. After the training, neural network has been tested through a comparison with the NASA equations and JANAF equations, showing the capability to cover with a single model wide range of temperature with an accuracy equal or greater than others mathematical function. Thermodynamic properties of gases have been calculated depending on temperature.

The present work deals with tests on a DI Diesel engine equipped with two different types of Common Rail injectors, the second one allowing a “smoother” fuel rate in the first stage of injection. The work aims at understanding how injection parameters and different injection rates may affect the combustion process in terms of in-cylinder pressure, noise and vibrations of the engine block. The tests performed for the same engine torque generally showed that engine speed, injection pressure and pilot injection duration are the most significant parameters that affect engine noise emissions. As regards the injection rate modulation, experiments showed that it is possible to reduce combustion noise at low engine speeds if the initial rate of injection is lower during the first stage of injection.

The internal mixture formation by gasoline direct injection offers a remarkable potential to improve the engine performances and to reduce the pollutant emission, due to the large possibilities of process control. On the other hand, the control mechanisms their selves are more complex and sensitive at speed or load variations than the ones used for external mixture formation. The spray characteristics, as well as the shape of injection rate have to be accurately adapted to every condition of load, speed and surrounding. This paper presents a method for the effective optimization of GDI techniques for SI engines, which is exemplified by a system with direct injection by high pressure modulation. The method is based on the interactive optimization of the processes within the injection system respectively during the spray evolution, by a feed-back strategy between separate numerical simulations of both processes.

The present work deals with the study of the dynamic behavior of a commercial injector subject to multiple injection strategy. The global spray characteristics have been investigate as well. These studies have been carried out using two numerical codes opportunely modified in order to better simulate the injection process. Comparisons between simulation results and experimental investigations have been made in order to test the reliability of the models. This paper aims at characterizing the macro and microscopic behavior of high pressure Diesel sprays generated by a common rail injector. If it is possible, purpose of this research is to validate and to extend the different correlations available in literature to the case of sprays generated by common rail injectors, especially at high injection pressures.

Water injection effects on combustion phenomena have been investigated for several years, from both a theoretical and experimental viewpoints due to the collaboration of AGIP PETROLI and ISAB ERG Refinery. In this paper the effects of water injection on diesel combustion are investigated and reported. Using single cylinder CFR engine Cetane (AGIP PRIOLO Engine 11361/1) cetane number (C.N.) and NOx emissions have been measured. Tests were performed according to ASTM Cetane Method (ASTM X2.7.4). Water was supplied by a continuous injection system. The engine was fed with a base diesel oil from DA1302 Refinery plant. The water to fuel mass ratio was varied in the range of 0 to 1.5. Apparent heat release and fuel mass burning rate analysis of the in-cylinder pressure data were carried out. The results of in-cylinder pressure data analysis have shown the effects of internal refrigeration on the compression work and on the combustion phenomena.

It is well-known that the reliability of calculations in ICEs depends on the accuracy of gases thermodynamic properties model. Several relationships modeling the composition of unburned and burned mixtures have been developed for computer use. In this paper, the authors have determined new relationships suitable also for ICEs applications, in order to calculate the enthalpy for various gases, and mixtures. These relationships can be used in the models describing the processes of intake, compression, combustion and expansion, to simulate a complete engine cycle and to foresee engine performance. These relationships have the functional form of a “V order Logarithmic Polynomial”, and they can be used in temperature range of practical interest.

Though analysed by a few researches, the practice of water injection in Spark Ignition Engines (SI-ICE) does not yield homogeneous results, owing to various typologies of engines used for experiments. In this paper the effects of water injection in the intake pipe are investigated from both a theoretical and experimental viewpoint. Pressure vs. time diagrams were recorded on a single-cylinder CFR engine at AGIP PETROLI, Priolo (CT). Tests were performed according to Research and Motor Method (ASTM). Water was supplied by a continuous injection system inclusive of comparatively high pressure pump. The engine was fed with low O.N. base gasoline (cheap products, intermediate of refinery processes). The water to fuel mass flow rate ratio was varied in the range 0 to 1.5. The NOx emissions measurements confirm the tremendous effectiveness of water injection in reducing the engine environmental impact.