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Nowadays, an automotive DI Diesel engine is demanded to provide an adequate power output together with limit-complying NOx and soot emissions so that the development of a specific combustion concept is the result of a trade-off between conflicting objectives. In other words, the development of a low-emission DI diesel combustion concept could be mathematically represented as a multi-objective optimization problem. In recent years, genetic algorithm and CFD simulations were successfully applied to this kind of problem. However, combining GA optimization with actual CFD-3D combustion simulations can be too onerous since a large number of simulations is usually required, resulting in a high computational cost and, thus, limiting the suitability of this method for industrial processes.

Knock control systems based on engine block vibrations analysis are widely adopted in passenger car engines, but such approach shows its main limits at high engine speeds, since knock intensity measurement becomes less reliable due to the increased background mechanical noise. For small two wheelers engines, knock has not been historically considered a crucial issue, mainly due to small-sized combustion chambers and mixture enrichment. Due to more stringent emission regulations and in search of reduced CO2 emissions, an effective on-board knock controller acquires today greater importance also for motorcycle applications, since it could protect the engine when different fuel types are used, and it could significantly reduce fuel consumption (by avoiding lambda enrichment and/or allowing higher compression ratios to be adopted). These types of engines typically work at high rotational speeds and the reduced signal to noise ratio makes knock onset difficult to identify.

The increasing environmental concern is leading to the need for innovation in the field of internal combustion engines, in order to reduce the carbon footprint. In this context, hydrogen is a possible mid-term solution to be used both in conventional-like internal combustion engines and in fuel cells (for hybridization purposes), thus, hydrogen combustion characteristics must be considered. In particular, the flame of a hydrogen combustion is less subjected to the quenching effect caused by the engine walls in the combustion chamber. Thus, the significant heating up of the thin lubricant layer upon the cylinder liner may lead to its evaporation, possibly and negatively affecting the combustion process, soot production. The authors propose an analysis which aims to address the behavior of different typical engine oils, (SAE0W30, SAE5W30, SAE5W40) under engine thermo-physical conditions considering a large hydrogen-fuelled engine.

The next steps of the current European and US legislation, EURO 6c and LEV III, and the incoming new test cycles will impose more severe restrictions on pollutant emissions for Gasoline Direct Injection (GDI) engines. In particular, soot emission limits will represent a challenge for the development of this kind of engine concept, if injection and after-treatment systems costs are to be minimized at the same time. The paper illustrates the results obtained by means of a numerical and experimental approach, in terms of soot emissions and combustion stability assessment and control, especially during catalyst-heating conditions, where the main soot quantity in the test cycle is produced. A number of injector configurations has been designed by means of a CAD geometrical analysis, considering the main effects of the spray target on wall impingement.

During the last years the deep re-examination of the engine design for lowering engine emissions involved two-wheel vehicles too. The IC engine overall efficiency plays a fundamental role in determining final raw emissions. From this point of view, the optimization of the in-cylinder flow organization is mandatory. In detail, in SI engines the generation of a coherent tumble vortex having dimensions comparable to the engine stroke could be of primary importance to extend the engines' ignition limits toward the field of the dilute/lean mixtures. For motorbike and motor scooter applications, the optimization of the tumble generation is considered an effective way to improve the combustion system efficiency and to lower emissions, considering also that the two-wheels layout represents an obstacle in adopting the advanced post-treatment concepts designed for automotive applications.

Combustion phasing is crucial to achieve high performance and efficiency: for gasoline engines control variables such as Spark Advance (SA), Air-to-Fuel Ratio (AFR), Variable Valve Timing (VVT), Exhaust Gas Recirculation (EGR), Tumble Flaps (TF) can influence the way heat is released. The optimal control setting can be chosen taking into account performance indicators, such as Indicated Mean Effective Pressure (IMEP), Brake Specific Fuel Consumption (BSFC), pollutant emissions, or other indexes inherent to reliability issues, such as exhaust gas temperature, or knock intensity. Given the high number of actuations, the calibration of control parameters is becoming challenging.

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.

The high number of hull losses is a main concern in the UAV field, mostly due to the high cost of on-board equipment. A crashworthiness design can be helpful to control the extent and position of crash impact damage, minimizing equipment losses. However, the wide use of composite materials has recently put the accent on the lack of data about the behavior of these structures under operative loads, such as the crash conditions. This paper presents the outcome of a set of tests carried out to achieve a controlled crush of UAV structures, and to maximize the Specific Energy Absorption. In this work, a small-scale experimental test able to characterize the energy absorption of a Carbon-fiber-reinforced polymer under compression was developed introducing self-supporting sinusoidal shape specimens, which avoid the need for complex anti-buckling devices.

This paper presents an optimization algorithm, based on discrete dynamic programming, that aims to find the optimal control inputs both for energy and thermal management control strategies of a Plug-in Hybrid Electric Vehicle, in order to minimize the energy consumption over a given driving mission. The chosen vehicle has a complex P1-P4 architecture, with two electrical machines on the front axle and an additional one directly coupled with the engine, on the rear axle. In the first section, the algorithm structure is presented, including the cost-function definition, the disturbances, the state variables and the control variables chosen for the optimal control problem formulation. The second section reports the simplified quasi-static analytical model of the powertrain, which has been used for backward optimization. For this purpose, only the vehicle longitudinal dynamics have been considered.

Fork system is a primary component for motorcycles because it assures the contact between tires and road, therefore the safety and the driving feeling. Usually fork optimization and tuning are experimentally made involving the generation of a high large number of prototypes and an expensive experimental campaign. To reduce the design and the tuning phases of a generic damper system, the numerical simulation should be considered. In this paper, a one-dimensional (1D) model of fore-carriage forks for road applications is presented. The model was built-up in AMESim code. In particular, the authors’ attention was focused on the detection and analysis of cavitation phenomenon inside the fork. As well known, the cavitation is a complex three-dimensional (3D) phenomenon that implies the phase transition.

The need for strategies that allow managing combustion in an adaptive way has recently widely increased. Especially Diesel engines aimed for clean combustion require a precise control of the combustion outputs. Acoustic emission of internal combustion engines contains a lot of information related to engine behavior and working conditions. Mechanical noise and combustion noise are usually the main contributions to the noise produced by an engine. Combustion noise in particular can be used as an indicator of the combustion that is taking place inside the combustion chamber and therefore as a reference for the control strategy. This work discusses the correlations existing between in cylinder combustion and the acoustic emission radiated by the engine and presents a possible approach to use this signal in the engine management system for control purposes.

In order to reduce both polluting emissions and fuel costs, many countries allow mixing ethanol to gasoline either in fixed percentages or in variable percentages. The resulting fuel is labeled E10 or E22, where the number specifies the ethanol percentage. This operation significantly changes way the stoichiometric value, which is the air-to-fuel mass ratio theoretically needed to completely burn the mixture. Ethanol concentration must be correctly estimated by the Engine Management System to optimally control exhaust emissions, fuel economy and engine performance. In fact, correct fuel quality recognition allows estimating the actual stoichiometric value, thus allowing the catalyst system to operate at maximum efficiency in any engine working point. Moreover, also other essential engine control functions should be adapted in real time by taking into account the quality of the fuel that is being used.

Upcoming more stringent emission regulations throughout the world pose a real challenge, especially in regard to Diesel systems for passenger cars, where the need of additional after-treatment has a big impact in terms of additional system costs and available packaging space. Therefore, the need for strategies that allow managing combustion towards lower emissions, that require a precise control of the combustion outputs, is definitely increasing. Acoustic emission of internal combustion engines contains a large amount of information related to engine behavior and working conditions. Mechanical noise and combustion noise are usually the main contributions to the noise produced by an engine. In particular, recent research from the same authors of this paper demonstrated that combustion noise can be used as an indicator of the combustion that is taking place inside the combustion chamber and therefore as a reference for the control strategy.

Nowadays, compression-ignited engines are considered the most efficient and reliable technology for automotive applications. However, mainly due to the current emission regulations, that require increasingly stringent reductions of NOx and particulate matter, the use of diesel-like fuels is becoming a critical issue. For this reason, a large amount of research and experimentation is being carried out to investigate innovative combustion techniques suitable to simultaneously mitigate the production of NOx and soot, while improving engine efficiency. In this scenario, the combined use of compression-ignited engines and gasoline-like fuels proved to be very promising, especially in case the fuel is directly-injected in the combustion chamber at high pressure. The presented study analyzes the combustion process produced by the direct injection of small amounts of gasoline in a compression-ignited light-duty engine.

The recent search for extremely efficient spark-ignition engines has implied a great increase of in-cylinder pressure and temperature levels, and knocking combustion mode has become one of the most relevant limiting factors. This paper reports the main results of a specific project carried out as part of a wider research activity, aimed at modelling and real-time controlling knock-induced damage on aluminum forged pistons. The paper shows how the main damage mechanisms (erosion, plastic deformation, surface roughness, hardness reduction) have been identified and isolated, and how the corresponding symptoms may be measured and quantified. The second part of the work then concentrates on understanding how knocking combustion characteristics affect the level of induced damage, and which parameters are mainly responsible for piston failure.

Today, the contribution of the transportation sector on greenhouse gases is evident. The fast consumption of fossil fuels and its impact on the environment have given a strong impetus to the development of vehicles with better fuel economy. Hybrid electric vehicles fit into this context with different targets, starting from the reduction of emissions and fuel consumption, but also for performance and comfort enhancement. Lamborghini has recently invested in the development of a hybrid super sport car, due to performance and comfort reasons. Aventador series gearbox is an Independent Shift Rod gearbox with a single clutch and during gear shifts, as all the single clutch gearbox do, it generates a torque gap. To avoid the additional weight of a Dual Clutch Transmission, a 48V Electric Motor has been connected to the wheels, in a P3 configuration, to fill the torque gap, and to habilitate regenerative braking and electric boost functions.

The Common-rail injection system has allowed achieving a more flexible fuel injection control in DI-diesel engines by permitting a free mapping of the start of injection, injection pressure, rate of injection. All these benefits have been gained by installing this device in combustion chambers born to work with the conventional distributor and in-line-pump injection systems. Their design was aimed to improve air-fuel mixing and therefore they were characterized by the adoption of high-swirl ports and re-entrant bowls. Experiments have shown that the high injection velocities induced by common rail systems determine an enhancement of the air fuel mixing. By contrast, they cause a strong wall impingement too. The present paper aims to exploit a new configuration of the combustion chamber more suited to CR injection systems and characterized by low-swirl ports and larger bowl diameter in order to reduce the wall impingement.

The water injection is one of the recognized technologies capable of helping the future engines to work at full load conditions with stoichiometric mixture. In the present work, a methodology for the CFD simulation of reacting flow conditions using AVL Fire code v. 2020 is applied for the assessment of the water injection effect on modern GDI engines. Both Port Water Injection and Direct Water Injection have been tested for the same baseline engine configuration under reacting flow conditions. The ECFM-3Z model adopted for combustion and knock simulations have been performed by adopting correlations for laminar flame speed, flame thickness and ignition delay times prediction, to consider the modified chemical behavior of the mixture due to the added water vapor.

This paper shows the influence of different battery charge management strategies on the fuel economy of a hybrid parallel axle-split vehicle in a real driving scenario, for a vehicle control system that has the additional possibility to split the torque between front and rear axles. The first section regards the validation of a self-developed Model in the Loop (MiL) environment of a P1-P4 plug-in hybrid electric car, using experimental data of a New European Driving Cycle test. In its original version, which is implemented on-board the vehicle, the energy management supervisor implements a heuristic, or rule-based, Energy Management Strategy (EMS). During this project, a different EMS has been developed, consisting of a sub-optimal control scheme called Equivalent Consumption Minimization Strategy (ECMS), explained in detail in the second section.

The continuous development of modern Internal Combustion Engine (ICE) management systems is mainly aimed at complying with upcoming increasingly stringent regulations throughout the world. Performing an efficient combustion control is crucial for efficiency increase and pollutant emissions reduction. These aspects are even more crucial for innovative Low Temperature Combustions (such as RCCI), mainly due to the high instability and the high sensitivity to slight variations of the injection parameters that characterize this kind of combustion. Optimal combustion control can be achieved through a proper closed-loop control of the injection parameters. The most important feedback quantities used for combustion control are engine load (Indicated Mean Effective Pressure or Torque delivered by the engine) and center of combustion (CA50), i.e. the angular position in which 50% of fuel burned within the engine cycle is reached.