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The limited thermal efficiency in internal combustion engines provides a partial transformation of fuel energy in net power. The heat lost through the exhaust gases represent a significant portion of energy looses. The Seebeck Effect is the direct conversion of temperature differences between two dissimilar metals or semiconductors into electrical voltage. The present study demonstrates the application of thermoelectric generators technology in Baja SAE vehicles to recovery exhaust heat looses, using thermal energy converter devices. The electrical energy produced in Seebeck Effect Cells, assembly in engine exhaust manifold, is conditioned and applied in vehicle batteries and supply energy consumption during vehicle operation. This action could increase the vehicle energy efficiency by the recovery the thermal energy dissipated. This extra power supply makes possible the reduction of on board batteries charge capacity and also recharges them without external power sources.

The pollutants emitted by fuel burn in an internal combustion engine are harmful to humankind health. One of undesirable pollutants are the nitrogen oxides (NOx), witch in the presence of sunlight is responsible by photochemical mist, forming products that irritates eyes, respiratory system and may damage plants. The present article aims to present the theoretical potential reduction in volumetric emissions of nitrogen oxides (NOx) in an internal combustion engine operating with the torch ignition system and homogeneous charge. Therefore, a calculation methodology based in measured pressures and determined temperatures were implemented to check the potential reduction in these pollutant emissions. The presented methodology used to estimate the NOx formation is based in NO formation model presented by [1].

A global effort has been made by the scientific community to promote significant reduction in vehicle engine out-emission. To comply with this goal a stratified torch ignition (STI) engine is built from a commercial existing baseline engine. In this system, combustion starts in a pre-combustion chamber, where the pressure increase pushes the combustion jet flames through calibrated nozzles to be precisely targeted into the main chamber. These combustion jet flames are endowed with high thermal and kinetic energy, being able to generate a stable lean combustion process. The high kinetic and thermal energy of the combustion jet flame results from the load stratification. The engine out-emissions of CO, HC and CO2 of the STI engine are presented, analyzed and compared with the baseline engine. The STI engine showed a significant decrease in the specific emissions of CO and CO2.

Global climate change and an increasing energy demand are driving the scientific community to further advance internal combustion engine technology. Invented by Sr. Henry Ricardo in 1918 the torch ignition system was able to significantly decrease engine’s fuel consumption and emission levels. Since the late 70s, soon after the Compound Vortex Controlled Combustion (CVCC) created by Honda, the torch ignition system R&D almost ceased due to the issues encountered by very complex and costly mechanic control systems that time. This work presents a stratified torch ignition prototype endowed with a sophisticated electronic control systems and components such as electro-injectors from direct injection systems placed on the pre-combustion chamber. The torch ignition prototype was tested and its performance are presented and compared with the baseline engine, which was used as a workhorse for the prototype engine construction.

The emission of nitric oxide (NOx) is the most difficult to limit among numerous harmful exhaust gas components. The NOX emission of internal combustion engines is mainly NO, but it will be oxidized into NO2 quickly after entering the air. NO is formed inside the combustion chamber in post-flame combustion by the oxidation of nitrogen from the air in conditions that are dependent on the chemical composition of the mixture, temperature and pressure. The correlation between NO emissions and temperature in the combustion chamber is a result of the endothermic nature of these reactions and can be described by extended Zeldovich Mechanism. The stratified torch ignition engine is able to run with lean mixture and low cyclic variability. Due to lean operation, the in-cylinder temperature of the STI engine is significantly lower than the conventional spark ignited one. This fact lead to a substantial reduction in NOx specific emission.

The Stratified Torch Ignition (STI) engine is capable of operating with lean mixture and low cyclic variability. These characteristic significantly decreases fuel consumption and emission levels. In the STI engine the combustion starts at a pre-combustion chamber where a stoichiometric mixture is ignited by an electrical spark. Pressure increase in the pre-combustion chamber push the combustion jet flames through a calibrated nozzle to be precisely targeted into the main chamber. These combustion jet flames endowed with high thermal and kinetic energy assures a fast and stable combustion of a lean mixture formed at the main chamber. A STI prototype were built and tested. The main combustion parameters were obtained from the in-cylinder pressure measured during the experiments. A combustion analysis is carried out to explain the significant improvement of the STI engine in regard to the baseline engine which was used as workhorse for the prototype engine construction.

A burning process in a combustion chamber of an internal combustion engine is very important to know the maximum temperature of the gases, the speed of combustion, and the ignition delay time of fuel and air mixture exact moment at which ignition will occur. The automobilist industry has invested considerable amounts of resources in numerical modeling and simulations in order to obtain relevant information about the processes in the combustion chamber and then extract the maximum engine performance control the emission of pollutants and formulate new fuels. This study aimed to general construction and instrumentation of a shock tube for measuring shock wave. As specific objective was determined reaction rate and ignition delay time of ethanol doped with different levels of additive enhancer cetane number. The results are compared with the delays measured for the ignition diesel and biodiesel.

The internal combustion engines require an efficient cooling system, the high temperatures generates at the time of combustion, reaching 2500 K peak burned gas. The materials used in the construction of the cylinder must operate within a maximum value, as well as the fluid film of lubricant oil. A bad dimensioned cooling system can lead to serious consequences such as loss of engine performance and/or efficiency, pre-ignition and increased exhaust emissions and may even lead to the destruction of the engine. In the torch ignition system overheating of the pre-chamber is even more critical and may lead to significant losses. Thus the torch ignition system requires an efficient cooling to prevent deterioration of the pre-chamber and consequently the engine caused by overheating. The solution proposed to resolve this inconvenience is the use of the cooling gallery in the cylinder head, for cooling the pre-chamber that is selected.

Global trends in the development of spark ignition internal combustion engines lead to the adoption of solutions that reduce CO2 emissions and fuel consumption. Downsizing is a well-established path for this reduction, but it is necessary to use other technologies in order to achieve these ever more rigorous levels. A homogeneous torch ignition system is a viable alternative for reducing CO2 emissions with a combined reduction in specific fuel consumption and increased thermal efficiency. Thus a prototype adapted from an Otto engine with four cylinders is used for analysis. The performance and CO2 emission reference data were initially obtained with the baseline engine operating with a stoichiometric mixture. Then for the same conditions of BMEP, angular velocity and gradual lean of the mixture from the stoichiometry, the results of the adapted system are obtained.

An torch ignition system with homogeneous charge is numerically analyzed using a one-dimensional computational model. The new ignition system is implemented in a four-cylinder engine, spark ignition, 1600 cm3, 16 valves. Parameters such as mass burn fraction profile and pressure vs crank angle are compared with experimental data obtained with the torch ignition system operating homogeneous charge with stoichiometric mixture. The computational model uses information such as the pre-chamber pressure as a function of crack angle, intake and exhaust pressure, volumetric efficiency, maps of injection and ignition, valve discharge and valve intake coefficient, lifting valve, laminar flame speed, among others parameters.

A burning process in a combustion chamber of an internal combustion engine is very important to know the maximum temperature of the gases, the speed of combustion, the ignition delay time of fuel and air mixture exact moment at which ignition will occur. The automobilist industry has invested considerable amounts of resources in numerical modeling and simulations in order to obtain relevant information about the processes in the combustion chamber and then extract the maximum engine performance control the emission of pollutants and formulate new fuels. This study aimed to general construction and instrumentation of a shock tube for measuring shock wave. As specific objective was determined reaction rate and ignition delay time of diesel, biodiesel and ethanol doped with different levels of additive enhancer cetane number. The results are compared with the ignition delay times measured for other authors.

The analysis of engine’s performance, gas emissions and combustion parameters is critical in the development of internal combustion engines. The combustion parameters analysis provide important information to speed up real-time engine’s operation in order to shorter the process of engine’s map calibration. The real-time analysis of these parameters allows the detection of anomalies, such as the prediction of knocking event. From the measurement of the In-cylinder pressure curve and the use of a one-zone combustion model is possible to evaluate the heat release rate, mass burned fraction and average In-cylinder gas temperature. Aiming to expand the amount of real-time data available, such as unburned and burned gases temperature and volume, radius and velocity of turbulent spherical flame and turbulence factor, this paper presents a hybrid combustion model, being composed by coupling a two-zone model to a one-zone model.

This work shows procedures for analyzing sprays produced by a direct injection injector. The parameters studied were tip penetration, spray pattern, cone angles and velocity profiles. Two different experimental procedures were applied. The first one to get knowledge of the initial stage of injection consisted in recording images in 4000 Hz. With the data obtained, the penetrations and penetration rates were evaluated. The second experimental procedure consisted of using the Particle Image Velocimetry technique to get images and velocity data for getting knowledge of spray pattern, external and internal cone angle and velocity profiles of the spray fully developed. Gasoline and ethanol were the two fluids tested on the experiments. The results showed larger cone angles for gasoline, linear decreasing behavior for velocities on the linear velocity profiles and a transient stage for the magnitude of the velocities in the initial stage of injection.

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.

Atmospheric pollution is the major public health issue in many cities around the world. Internal combustion engines (ICE) and industries are common sources of pollutants that aggravate this situation. Aiming to overcome this problem, increasingly restrictive legislation on combustion pollutant emissions has been formulated and new technologies are being developed to ensure compliance with such restrictions. In this scenario, the lean mixtures appear as a possible alternative, but also bring some inconveniences such as combustion instabilities. Pre-chamber ignition systems (PCIS) enable a more stable combustion process due to high kinetic, thermal and chemical energy of the gases from the pre-chamber (PC), which pass through nozzles and begin the combustion process of the air-fuel mixture contained in the main combustion chamber (MC). However, some challenges still have to be overcome in the development of these systems, one of the main ones being hydrocarbon (HC) emissions.

It developed a design and construction methodology of a stratified charge torch ignition system for an Otto engine aiming fuel consumption and pollutant emission reduction. The torch ignition system is made of a combustion pre-chamber equipped with a direct fuel injector, an air injector and a spark plug. Fuel is directly injected in the pre-chamber aiming the formation of a lightly rich air fuel mixture. The combustion process starts in the pre-chamber and as the pressure rises, combustion jet flames are produced through interconnection nozzles into the main chamber. The high thermal energy of the jet flames reduces the combustion time, increases the combustion efficiency and allows the engine to efficiently burn lean air fuel mixture of several kinds of fuel in the main chamber, even those that are difficult to ignite. After the combustion takes place in the pre-chamber, air is also injected to help the exhaust process of the combustion products of the previous cycle.

The trends in the development of spark ignition engines leads to the adoption of lean mixtures in the combustion chamber. Torch ignition systems have potential to reduce simultaneously the NOx and CO emissions, while keeping the fuel conversion efficiency at a high level. This study aims to design and analyze a torch ignition system running with ethanol on lean homogeneous charge, adapted to an Otto cycle single-cylinder engine with optical visualization. The main objective is to achieve combustion stability under lean burn operation and to expand the flammability limit for increasing engine efficiency by means of redesigning the ignition system adapting a pre-chamber to the main combustion chamber. Experiments were conducted at constant speed (1000 rpm) using ethanol (E100) as fuel, for a wide range of injection, ignition and mixture formation parameters. Specific fuel consumption and combustion stability were evaluated at each excess air ratio.

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.

This paper discusses the importance of vibration transmitted from the ground to the driver from the perspective of human whole-body vibration (WBV). The scope of analysis is to compare the main vehicle frequencies with those important from the human vibration health and comfort point of view. That was performed by mapping the vibration transmissibility present in different sub sections of the vehicle. The first is the transmissibility between the axles and the chassis rail, the following between the chassis rail and the cabin. The last would be between the cabin and the drivers' seat, although that was not possible from the acquisition point of view. The vehicles measured have mechanical suspension and elastomeric cabin coupling. It is known that all suspension systems in vehicle are highly nonlinear, although here linear dynamic analysis methods were used.

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.