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The integration of the exhaust manifold in the engine cylinder head has received considerable attention in recent years for automotive gasoline engines, due to the proven benefits in: engine weight diminution, cost saving, reduced power enrichment, quicker engine and aftertreatment warm-up, improved packaging and simplification of the turbocharger installation. This design practice is still largely unknown in diesel engines because of the greater difficulties, caused by the more complex cylinder head layout, and the expected lower benefits, due to the absence of high-load enrichment. However, the need for improved engine thermomanagement and a quicker catalytic converter warm-up in efficient Euro 6 diesel engines is posing new challenges that an integrated exhaust manifold architecture could effectively address. A recently developed General Motors 1.6L Euro 6 diesel engine has been modified so that the intake and exhaust manifolds are integrated in the cylinder head.

The use of Ducted Fuel Injection (DFI) for attenuating soot formation throughout mixing-controlled diesel combustion has been demonstrated impressively effective both experimentally and numerically. However, the last research studies have highlighted the need for tailored engine calibration and duct geometry optimization for the full exploitation of the technology potential. Nevertheless, the research gap on the response of DFI combustion to the main engine operating parameters has still to be fully covered. Previous research analysis has been focused on numerical soot-targeted duct geometry optimization in constant-volume vessel conditions. Starting from the optimized duct design, the herein study aims to analyze the influence of several engine operating parameters (i.e. rail pressure, air density, oxygen concentration) on DFI combustion, having free spray results as a reference.

A methodology for an efficient failure prediction of automotive steel wheels during fatigue experimental tests is proposed. The strategy joins the CDTire simulative package effectiveness to a specific wheel finite element model in order to deeply monitor the stress distribution among the component to predict damage. The numerical model acts as a Software-in-the-loop and it is calibrated with experimental data. The developed tool, called VirtualWheel, can be applied for the optimisation of design reducing prototyping and experimental test costs in the development phase. In the first section, the failure criterion is selected. In the second one, the conversion of hardware test-rig into virtual model is described in detail by focusing on critical aspects of finite element modelling. In conclusion, failure prediction is compared with experimental test results.

A real-time mean-value engine model for the simulation of the HRR (heat release rate), in-cylinder pressure, brake torque and pollutant emissions, including NOx and soot, has been developed, calibrated and assessed at both steady-state and transient conditions for a Euro 6 1.6L GM diesel engine. The chemical energy release has been simulated using an improved version of a previously developed model that is based on the accumulated fuel mass approach. The in-cylinder pressure has been evaluated on the basis of the inversion of a single-zone model, using the net energy release as input. The latter quantity was derived starting from the simulated chemical energy release, and evaluating the heat transfer of the charge with the walls. NOx and soot emissions were simulated on the basis of semi-empirical correlations that take into account the in-cylinder thermodynamic properties, the chemical energy release and the main engine parameters.

One of the key technologies for the improvement of the diesel engine thermal efficiency is the reduction of the engine heat transfer through the thermal insulation of the combustion chamber. This paper presents a numerical investigation on the effects of the combustion chamber insulation on the heat transfer, thermal efficiency and exhaust temperatures of a 1.6 l passenger car, turbo-charged diesel engine. First, the complete insulation of the engine components, like pistons, liner, firedeck and valves, has been simulated. This analysis has showed that the piston is the component with the greatest potential for the in-cylinder heat transfer reduction and for Brake Specific Fuel Consumption (BSFC) reduction, followed by firedeck, liner and valves. Afterwards, the study has been focused on the impact of different piston Thermal Barrier Coatings (TBCs) on heat transfer, performance and wall temperatures.

The paper deals with the design and manufacturing of a McPherson suspension arm made from short glass fiber reinforced polyamide (PA66). The design of the arm and the design of the molds have been made jointly. According to Industry 4.0 paradigms, a full digitalization of both the product and process has been performed. Since the mechanical behavior of the suspension arm strongly depends on constraints which are difficult to be modelled, a simpler structure with well-defined mechanical constraints has been developed. By means of such simple structure, the model for the behavior of the material has been validated. Since the suspension arm is a hybrid structure, the associated simple structure is hybrid as well, featuring a metal sheet with over-molded polymer. The issues referring to material flow, material to material contact, weld lines, fatigue strength, high and low temperature behavior, creep, dynamic strength have been investigated on the simple structure.

Developing of innovative technologies and materials to meet the requirements of environmental legislation on vehicle emissions has paramount importance for researchers and industries. Therefore, improvement of engine efficiency and fuel saving of modern internal combustion engines (ICEs) is one of the key factors, together with the weight reduction. Thermoplastic composite materials might be one of the alternative materials to be employed to produce engine components to achieve these goals as their properties can be engineered to meet application requirements. Unidirectional carbon fiber reinforced PolyEtherImide (CF/PEI) thermoplastic composite is used to design engine connecting rod and wrist pin, applying commercial engine data and geometries. The current study is focused on some elements of the crank mechanism as the weight reduction of these elements affects not only the curb weight of the engine but the overall structure.

The Atmospheric Revitalization System (ARS) provides carbon dioxide removal, trace contaminant control, and gas constituent analysis. In this field, the interest of RecycLAB [5], the TAS-I Advanced Live Support Research & Development laboratory is directed to trace gas contaminants removal and monitoring. During manned space mission, the decontamination of cabin or rack air after contingency events such as fire or pyrolysis is a priority for the crew safety. In this paper, basic zeolites, obtained by impregnation of common zeolites with a basic oxide, are used to remove acid gas contaminants from air stream. A multi-functional system, able to accommodate reactors of different shape, characteristics and set-up, is used at this purpose. This breadboard, called ZEUS (Zeolites for an Environmental-control Unit in Space), is made of AISI 316L stainless steel and consists of a closed loop, in which the inner volume is completely isolated from the external environment.

Thermo-structural analysis of components is usually carried out by means of two FE models, one that solves the thermal problem and one that, using the results of the thermal model, computes strains and stresses. The interaction between the two models is based on the superposition principle, but it means that the mutual effects and the non-linearities between the two physical problems are neglected. In this paper a multiphysics approach based on the Cell Method is proposed and it is applied to a time dependent thermo-mechanical case study represented by an exhaust manifold simulacrum: the coupled thermal and mechanical problems are solved in an unique run, giving the opportunity to take into account mutual effects. Comparing the results with the traditional FE analysis the advantages in terms of accuracy and computational time achieved through the proposed methodology are highlighted.

Fuel cell vehicles promise to become, in near future, competitive with conventional cars in terms of performance, efficiency and compliance with emission reduction schedules. However, many steps still have to be done, and a series of fundamental choices, such as high vs. low air pressure system options remain unresolved. Modeling can be a powerful instrument to evaluate different components or plant layout, and to predict the dynamic behavior of a fuel cell system. The first part of this paper illustrates the implementation of a direct engineering dynamic model of a load-following fuel cell vehicle. The modeling techniques, assumptions and basic equations are explained for each subsystem, with special attention to the air supply system, whose dynamic simulation was one of the primary targets of this work. Some of the simulation results are presented in the second part.

This paper presents the modeling of the transient phase of catalyst heating on a high-performance turbocharged spark ignition engine with the aim to accurately predict the exhaust thermal energy available at the catalyst inlet and to provide a “virtual test rig” to assess different design and calibration options. The entire transient phase, starting from the engine cranking until the catalyst warm-up is completed, was taken into account in the simulation, and the model was validated using a wide data-set of experimental tests. The first step of the modeling activity was the combustion analysis during the transient phase: the burn rate was evaluated on the basis of experimental in-cylinder pressure data, considering both cycle-to-cycle and cylinder-to-cylinder variations.

In this work, several nanostructured ceria-based catalysts were prepared by the hydrothermal technique varying two synthesis parameters (namely, temperature and pH). Then, cerias with different shapes (i.e., cubes, rods, combination of them, other polyhedra) and structural properties were obtained. The prepared materials were tested for the CO oxidation and soot oxidation efficiency. The results have shown that, for the CO oxidation, activities depend on the surface properties of the catalysts. Conversely, for the soot oxidation, the most effective catalysts exhibit better soot-catalyst contact conditions.

The target for future cooling systems is to control the fluid temperatures and flows through a demand oriented control of the engine cooling to minimize energy demand and to achieve comfort, emissions, or service life advantages. The scope of this work is to create a complete engine thermal model (including both cooling and lubrication circuits) able to reproduce engine warm up along the New European Driving Cycle in order to assess the impact of different thermal management concepts on fuel consumption. The engine cylinder structure was modeled through a finite element representation of cylinder liner, piston and head in order to simulate the cylinder heat exchange to coolant or oil flow circuits and to predict heat distribution during transient conditions. Heat exchanges with other components (EGR cooler, turbo cooler, oil cooler) were also taken into account.

A fuel-cell-based system's performance is mainly identified in the overall efficiency, strongly depending on the amount of power losses due to auxiliary devices to supply. In such a situation, everything that causes either a decrease of the available power output or an increment of auxiliary losses would determine a sensible overall efficiency reduction.

The paper presents the main results of a study on the simulation of energy efficient management of on-board electric and thermal systems for a medium-size passenger vehicle featuring a parallel-hybrid diesel powertrain with a high-voltage belt alternator starter. A set of advanced technologies has been considered on the basis of very aggressive fuel economy targets: base-engine downsizing and friction reduction, combustion optimization, active thermal management, enhanced aftertreatment and downspeeding. Mild-hybridization has also been added with the goal of supporting the downsized/downspeeded engine performance, performing energy recuperation during coasting phases and enabling smooth stop/start and acceleration. The simulation has implemented a dynamic response to the required velocity and manual gear shift profiles in order to reproduce real-driver behavior and has actuated an automatic power split between the Internal Combustion Engine (ICE) and the Electric Machine (EM).

An innovative approach to the study of combustion and emission formation in modern diesel engines has been applied to a EURO V diesel engine equipped with an indirect-acting piezo injection system. The model is based on the joint use of a predictive non-stationary 1D spray model, which has recently been presented by Musculus and Kattke, and a diagnostic multizone thermodynamic model developed by the authors. The combustion chamber content has been split into homogeneous zones, to which mass and energy conservation laws have been applied: an unburned gas zone, made up of air, EGR and residual gas, several fuel/unburned gas mixture zones, premixed combustion burned gas zones and diffusive combustion burned gas zones. The 1D spray model enables the mixing process dynamics of the different fuel parcels with the unburned gas to be estimated for each injection pulse; therefore, the equivalent ratio time-history of each mixture zone can be estimated.

In the development of High Altitude Long Endurance (HALE) UAVs and their control the flexibility of the wing must be taken into account. The wing of this type of UAVs, usually made of highly flexible composite materials, has high aspect ratio with significant bending-torsional deformation during flight. The NASA Helios, as an example, has tragically shown that wing deformation coupled with control and power operation can cause serious problem in flight, instability can suddenly occur and can be quite difficult to foresee. In this paper the mathematical description of a flexible wing multibody model is presented. It is suitable to simulate the effect of both structural flexibility and flight dynamics and maneuvering on the wing deformation, and can be used to help developing control strategies for air vehicles with highly deformable wings.

The stability analysis of plates and shells in high speed flow deals with the determination of the flutter instability boundary. A linear analysis is made using the basic principles of the theory of aero-elasticity of isotropic bodies, the theories of flexible plates, the stability equations and associated boundary conditions obtained through a linear formulation. Herein, the nonlinear stability of flexible plate immersed in a high speed gas flow is considered. The model takes into account quadratic and cubic aerodynamic nonlinearities as well as cubic geometric nonlinearities. It is shown that the inclusion of quadratic aerodynamic nonlinear components can lead to the appearance of “amplitude-frequency” phenomena in both the pre-critical as well as in the post-critical flow speed regimes. The influence of the free stream flow speed on the “amplitude-frequency” dependence phenomena is also presented.

Three different ceramic substrate materials (Silicon Carbide, Cordierite and Aluminum Titanate) for a Diesel Particulate Filter (DPF) for a European passenger car diesel engine have been experimentally investigated in this work. The filters were soot loaded under real world operating conditions on the road and then regenerated in two different ways that simulate the urban driving conditions, which are the most severe for DPF regeneration, since the low exhaust flow has a limited capability to absorb the heat generated by the soot combustion. The tests showed higher temperature peaks, at the same soot loading, for Cordierite and Aluminum Titanate compared to the Silicon Carbide, thus leading to a lower soot mass limit, which in turn required for these components a higher regeneration frequency with draw backs in terms of fuel consumption and lube oil dilution.

An experimental investigation on a group of unleaded gasolines of different chemical composition has been carried out, in order to analyze their knock behaviour in a mass-produced engine at high revolution speed, to highlight possible inconsistencies with their standard Research and Motor octane numbers and to try to discover explanations for the abovementioned inconsistencies. The investigation has been focused on fuels containing oxygenated compounds, such as alcohols (methanol and ethanol) and ethers (MTBE), with the aim of pointing out the influence of the fuel composition on the octane rating, especially as far as the variation in the stoichiometric air/fuel ratio (due to oxygenated compounds blending) is concerned. In particular, the rating of all the fuels under the same relative air/fuel ratio has shown to be a mandatory condition in order to obtain a proper estimate of antiknock performances. The evaluations obtained are consistent with the standard Motor octane numbers.