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The recent advance in the development of various hybrid vehicle technologies comes along with the need of establishing optimal energy management strategies, in order to minimize both fuel economy and pollutant emissions, while taking into account an increasing number of state and control variables, depending on the adopted hybrid architecture. One of the objectives of this research was to establish benchmarking performance, in terms of fuel economy, for real time on-board management strategies, such as ECMS (Equivalent Consumption Minimization Strategy), whose structure has been implemented in a SIMULINK model for different hybrid vehicle concepts.

Metallic foams or sponges are materials with a cell structure suitable for many industrial applications, such as reformers, heat catalytic converters, etc. The success of these materials is due to the combination of various characteristics such as mechanical strength, low density, high specific surface, good thermal exchange properties, low flow resistance and sound absorption. Different materials and manufacturing processes produce different type of structure and properties for various applications. In this work a genetic algorithm has been developed and applied to support the design of catalytic devices. In particular, two substrates were considered, namely the traditional honeycomb and an alternative open-cell foam type. CFD simulations of pressure losses and literature based correlations for the heat and mass transfer were used to support the genetic algorithm in finding the best compromise between flow resistance and pollutant abatement.

An exhaust system comprises at least one muffler, the back pressure generated by the muffler exponentially grows as the engine speed increases. Accordingly, fuel consumption and direct CO2 emissions are penalized due to the back pressure generated by the muffling body in order to reduce noise emissions. To obviate this, it has been suggested to construct an exhaust system with two differentiated paths according to the engine speed, so that at low speeds the exhaust gases follow a first high acoustic attenuation (high back pressure) path, while at high speeds (high exhaust gas pressure), the exhaust gases follow a second low acoustic attenuation (low back pressure) path. Simulation and experimental analysis will be presented. A control valve is provided to alternatively direct the exhaust gases along the desired path according to the engine speed. These control valves usually include an electric or electro-pneumatic actuator, but are heavy, large in size and expensive.

In this work a multilevel CFD analysis have been applied for the design of an intake air-box with improved characteristics of noise reduction and fluid dynamic response. The approaches developed and applied for the optimization process range from the 1D to fully 3D CFD simulation, exploring hybrid approaches based on the integration of a 1D model with quasi-3D and 3D tools. In particular, the quasi-3D strategy is exploited to investigate several configurations, tailoring the best trade-off between noise abatement at frequencies below 1000 Hz and optimization of engine performances. Once the best configuration has been defined, the 1D-3D approach has been adopted to confirm the prediction carried out by means of the simplified approach, studying also the impact of the new configuration on the engine performances.

In modern turbocharged downsized GDI engines the achievement of maximum thermal efficiency is precluded by the occurrence of knock. In-cylinder pressure sensors give the best performance in terms of abnormal combustion detection, but they are affected by long term reliability issues and still constitute a considerable part of the entire engine management system cost. To overcome these problems, knock control strategies based on engine block vibrations or ionization current signals have been developed and are widely used in production control units. Furthermore, previous works have shown that engine sound emissions can be real-time processed to provide the engine management system with control-related information such as turbocharger rotational speed and knock intensity, demonstrating the possibility of using a multi-function device to replace several sensors.

A unique differential assembly was needed for the Lawrence Technological University (LTU) SAE Formula race car. Specifically, a differential was required that had torque sensing capabilities, perfect reliability, high strength, light weight, the ability to withstand inertia and shock loading, a small package, no leaks, the ability to support numerous components. In that regard, an existing differential was selected that had the torque sensing capabilities, but had deficiencies that needed to be fixed. Those deficiencies included the following: Differential unit was over 4 kg unmounted, with no housing. This was considered too heavy, when housed properly. Bearing surface was provided on only one end of the carrier. This design provides insufficient bearing surface to support either the differential housing or half-shafts The internal drive splines integral to the case are not optimized for a perpendicular drive/axle arrangement, such as, a chain drive.

It is well known that mufflers attenuate the engine noise essentially through dissipative and reflective effects. There is however another alternative technique for noise attenuation that has not been deeply explored, i.e. thermal acoustics. In fact the temperature of the gas influences the acoustic behaviour of the exhaust system; reducing the exhaust gas temperature, the sound pressure of the acoustic waves is reduced. This phenomenum could be used to improve the sound attenuation. We propose an experimental study of this phenomenum and of how it could be used to reduce the exhaust noise. We measured that, using in underfloor position passive heat exchangers like corrugated pipes, the exhaust gas quickly exchanges heat with the external environment and arrives to the rear muffler significantly colder. We observe about 2 dB decrease of the OA dB value when the gas temperature decreases of about 100°C.

External gear pumps are widely used in many different applications because of their relatively low costs and high performances, especially in terms of volumetric and mechanical efficiency. The main weaknesses of external gear pumps can be summarized as follows: 1 Sudden increase or decrease of pressure inside volumes between teeth, which could lead respectively to noise emissions and to cavitation onset; 2 Necessity of limiting power losses and increasing volumetric efficiency, obtainable by reducing leakage flows between components; 3 Need of maintaining an ad-hoc minimum lubrication film thickness. In recent years many efforts, in terms of mathematical models and experimental tests, were done in order to limit energy losses and noise emissions. With the aim of deeply studying dynamic behaviour of external gear pumps and addressing their design, a 1D model was developed by means AMESim® code.

Shock absorbers and damper systems are important parts of automobiles and motorcycles because they have effects on safety, ride comfort, and handling. In particular, for vehicle safety, shock absorber system plays a fundamental role in maintaining the contact between tire and road. Generally, to assure the best trade-off between safety and ride comfort, a fine experimental tuning on all shock absorber components is necessary. Inside a common damper system the presence of several conjugated actions made by springs, oil and pressurized air requires a significant experimental support and a great number of prototypes and test. Aimed to reduce the design and tuning phases of a damper system, it is necessary to join these phases together with a numerical modelling phase. The aim of this paper is to present the development of a mono-dimensional (1D) model for simulating dynamic behaviour of damper system.

The paper presents the main reasons for the increasing market share of vehicles with the capacity to run on random bio fuel blends. It describes the philosophy and basic layout of current integral flex mixture preparation systems. The paper demonstrates the necessity to introduce a series of new high-performance analysis tools for further improvement of the mixture preparation system and in particular the fuel injector performance. The paper continues with a discussion of the basic structure of the interactive Virtual Engine Model approach applied to fuel injector atomizer optimization. Test results obtained by application of the new tools to two different series production flex engines are presented. The impact of the improved spray formation capability of the optimized fuel injector atomizers is explained and experimental vehicle FTP-cycle data are reported and discussed.