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Due to the large negative impact of combustion gas emissions on air quality and the more stringent environmental legislation, research on internal combustion engines (ICE) are being developed to reduce emissions of pollutant gases to the atmosphere. One of the research fronts is the use of lean mixtures with the pre-chamber ignition system (PCIS). This system consists of a pre-chamber (PC) connected to the main chamber by one or more interconnecting holes. A spark plug initiates combustion of the mixture present in the pre-chamber, which is propagated as gas jet into the main chamber, igniting the lean mixture present therein. The gas jets have high thermal and kinetic energy, which promote faster combustion duration, making the system less prone to knock and with lower cyclic variability of the IMEP, enabling the lean limit extension. The pre-chamber system can be assisted with a supplementary liquid or gaseous fuel injection, enabling the charge stratification.

The torch ignition system consists in the inflammation of the air/fuel mixture by means of gases jet flames that constitute ignition lines. Engines with this feature have a cavity or combustion pre-chamber, physically separate from the main chamber. In these systems happens a larger turbulence generation, due the movement of the gases inside the pre-chamber and through the interconnection orifices. The charge stratification, by means of an auxiliary inlet fuel system, also contributes for the fast and insurance inflammation of lean mixtures and the most varied combustible, including the difficult direct spark ignition fuels. This work presents the design elaboration of combustion pre-chamber from an analysis of the influence of the main constructive parameters in the combustion process.

For metallic tanks in contact with aqueous solution, it is always observed the presence of electrochemical corrosion. This process can cause both economic and environmental damage. In the automotive industry, fuel tanks systems have been studied in order to propose new materials to replace the plastic tanks or tanks with metallic coatings. Plastic tanks have the disadvantage of not being recyclable. In the other hand, for metallic coated tanks, tin is used as a coat material and, for this reason, the external tank side must be painted, making its productive process more expensive and generating higher amount of waste. Nowadays, organic-metallic coated tanks, in which, nickel and aluminum are the metals present, can be found. These coatings show potential application; because they do not use heavy metals in their composition and they do not require external painting, allowing a lower production cost.

The growing demand for more efficient and less polluting engines has lead the scientific community to further develop the road map engine technologies, including direct fuel injection. Direct injection research demands the investigation of spray formation and its characteristics. The present work performs the characterization of the macroscopic parameters of ethanol sprays (E100) produced with a fuel gauge pressure of 80 bar and gauge back pressures of 0, 5 and 10 bar. The sprays analysis was performed using high speed filming by means of Shadowgraph technique. Computational routines of matrix analysis were applied to measure the spray cone angles, penetration and penetration rate. The spray visualization demanded an experimental apparatus composed of a pressurized cylinder with nitrogen, a fuel tank as pressure vessel, an injection driver equipped with a peak and hold module controlled by a MoteC M84, a Phantom V7.3 high speed camera and LEDs for illumination.

Environmental policies and fuel costs have driven the development of new technologies for internal combustion engines. In this sense, the use of mixtures with small portions of fuel allows lower fuel consumption and pollutants emissions, emerging as a promising strategy. Despite the advantages, lean burn requires a larger energy source to provide satisfactory flame propagation speed and consequently a stable combustion. The use of pre-chamber ignition systems (PCIS) has been used in SI engines to assist the start of combustion of lean mixtures, in which a supplementary fuel system can stratify the amount of either liquid or gaseous fuels supplied to the pre-chamber. In this context, this paper aims to evaluate combustion characteristics of a commercial engine with the use of stratified PCIS operating with impoverished mixtures of ethanol-air in main-chamber and hydrogen assistance in pre-chamber.

Extensive studies of pre-chamber ignition systems in internal combustion engines have proven its effectiveness in reduction of fuel consumption and improvement in several combustion parameters. Considering the different types of pre-chamber configurations, this paper aims to compare the combustion in a SI engine with both homogeneous and stratified pre-chamber ignition systems. To achieve this objective a system with the ability to control the hydrogen injection in the pre-chamber was built. This system was installed in a multi-cylinder Ford Sigma 1.6L engine and tested in a dynamometric room. Tests consisted in imposing a constant rotation and IMEP to test three conditions: standard spark ignition, pre-chamber ignition system without fuel injection (homogenous) and with hydrogen injection (stratified). It was possible to identify that with the use of pre-chamber ignition system there is a reduction in specific fuel consumption and in the combustion duration.

Stringent automotive emissions and fuel economy regulations have been bringing challenges for the development of new engine technologies to achieve greater levels of efficiency and pollutants reduction. In this scenario the homogeneous charge pre-chamber jet ignition system (HCJI) enables lean operation due the jet combustion gases emerging from the small pre-chamber combustor as the ignition source for main chamber combustion in an internal combustion engine. The present computational work was carrying out to investigate the interaction between the pre-chamber and main chamber fluid dynamics events. This CFD research was performed and validated with a experimental data for a single cylinder of a 4-stroke indirect fuel injection engine under the motoring condition running at 4500 rpm with 50% wide open throttle condition.