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The growing global need for energy and the aggravation of vehicular pollution, associated with a highly competitive market, demand fast and less expensive solutions to develop engine technologies. Numerical simulation has been an effective tool to help meet these needs, as it shortens the time and cost of current engine research. In this scenario, 1-D numerical model has been widely and successful used, presenting excellent results generally with errors around 5% in comparison with experimental data. In this work, the main performance parameters of an in-line four-cylinder SI engine is analyzed through a 1-D simulation using the GT-Power code. A full-scale engine model is set up, which is later calibrated by comparing with experimental data. The numerical methodology is carefully discussed and the methods regarding engine valve diagram and geometrical boundary conditions are also presented.

The work focuses on studying ethanol spray behavior injected directly inside a spark ignited internal combustion engine in the compression stroke. An experimental procedure for measuring spray penetration and spray overall cone angle produced by a multi-hole direct injector was developed by means of computational codes written in Matlab environment for working with images of spray injections and to acquire calculated results in an automatic way. The shadowgraph technique with back continuous illumination associated with a high speed recording image process was used in a single cylinder optical research engine for acquiring images of Brazilian ethanol fuel injected at 120° before the top dead center of compression stroke. The process of spray injections occurred with engine speeds of 1000 rpm, 2000 rpm and 3000 rpm. The results showed that spray penetrations decrease and spray cone angle increase when the engine speed is raised.

Vehicles powered by internal combustion engines correspond to 99.7% of the global fleet. Unfortunately, most of them runs with fossil fuels and contribute with over than 70% of CO and 20% of CO2 emitted to atmosphere. Global climate change has become a major issue and stringent legislation has been forcing the scientific community to seek a feasible solution for this issue. Renewable fuels, hybrid and electric vehicles have been pointed out as the answer for harmful greenhouse gases emissions. This paper demystifies the wrong belief that ICE will be totally replaced by electric vehicles in short and medium time. The zero emission vehicle (ZEV) terminology applied to EV must abolished since it is not true, as 65% of global electricity is generated from non-renewable sources. Despite of being more efficient, hybrid vehicles are still economically unfeasible.

This work presents the experimental determination of an automotive turbocharger flow map, by using a flux test stand. This equipment is able to reproduce and measure the main characteristics of an intake and exhaust flows of an automotive engine. To build the compressor and turbine flow maps, the experimental data should be treated through an empirical model. Flow maps of two turbochargers are presented. The first flow map presented was used to validate the data treating method. The validation process made use of published GT12 Garrett turbocharger data. The data treating method was applied on the experimental dada of T2 Garrett turbocharger obtained on the flux test stand. The flow maps build are shown, and operational limits are identified on then. These flow maps give essential information to choose the most suitable turbocharger for a specific internal combustion engine.

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.

A multi-hole direct injection injector was studied by means of image analysis. Methodologies based on an automatic process of cone angle measurement and edge detection were applied for the spray images generated by a 100 bar injection pressure discharged into a pressurized rigid chamber. A criterion based on pixel values was taken to localize the spray edges as angular coordinates and also with x and y position data. The high pixel values were associated with liquid phase while the low pixel values were associated to its absence. Computational codes written in MATLAB environment were used to analyze the numerical matrices associated to the images. Using the written MATLAB codes, a comparison of the effect of atmospheric back pressure, inside the chamber, on the spray pattern, cone angle and spray penetration were evaluated. The chamber was pressurized with 2.5, 5.0, 7.5 and 10 bar of back pressure. The tested fluid injected was EXXSOL D60 for simulating ethanol fuel behavior.

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.

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.

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.

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.

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.

In the present work it was studied the flow around the intake and discharge valves of the HONDA CBR 600RR Engine, used in Formula SAE by the team of CEFET-MG, Formula Cefast. Presenting the methodology and experimental results in the measurement of the reversal discharge coefficient of the intake port and the discharge coefficient of exhaust valve of the engine used in the prototype, serving as a starting point for further studies and development of the prototype drive system. These experimental tests were performed on the flow bench infrastructure of the Pontificia Universidade Católica de Minas Gerais, PUC-MG, using the engine head, same model as used in the Formula Cefast team prototype. Necessary parts and adaptations for tests were developed, such as a mechanism for opening and closing the valves during the experiment.

This paper applies numerical models to simulate the Onset of Knock (OK) in a commercial automotive spark ignition engine. Results from different models were compared with different knock detection methods to verify the best agreement. Despite being widely studied and reported in the literature, avoiding knock still poses a challenge to engine efficiency improvement and it is the focus of many new technologies. Knock detection methods rely on measurements of incylinder pressure or engine vibrations to determine the onset of knock, while some 0D predictive models are deduced from experimental data and correlations involving the critical parameters related to the knock phenomenon. Although 0D predictive models are easy to apply and calculate, the initial formulation and the different experimental conditions used to create each model often result in different numerical formulations.

The transportation sector is responsible for 24% of CO2 global emissions and great effort has been made by the scientific community to replace the use of fossil fuels with renewables. Brazil has committed to implement all obligations provided in COP26 seeking carbon neutrality in the set of economic activities. In this regard, Brazil has agreed in reducing GHG by 50% until 2030. Flexfuel technology was introduced in the Brazilian market decreasing fuel conversion efficiency due to the use of an intermediary compression ratio value, lower in comparison with the best value for engines exclusively fueled with ethanol and higher for gasoline. According to data published by INMETRO, flexfuel engine consumption has increased around 6%. Many European countries have been pointing to the electrification of the light vehicle as a solution to mitigate GHG, which is neither best nor a feasible solution for the future of Brazilian mobility.

The nitrogen oxide (NOx) emitted by the internal engines is an undesirable pollutant and responsible for the photochemical smog when reacts with ultraviolet light from the sun. This smog can cause eyes and respiratory system irritation as also damage plants. The torch ignition system has been proving to be a viable alternative for reducing NOx emissions, and it is one of the main attractions of the system. NOx formation is closely related to the system’s work temperature. Thus, determining the temperature in the pre-chamber is of fundamental importance, whereas the torch ignition system operating at a temperature above the specified, could lead to an increase in NOx emissions, in the probability of detonation and in the probability of pre-ignition, the possibility of limiting performance, an increase in mechanical efforts and deformation/ breakage.

Government regulations and the growing awareness of the general population about the impact caused on nature and human health by the pollutant emission from automobiles have increased the demand for a more environmentally friendly solution for the future of mobility. Considering the high cost of electric vehicles, the negative environmental impact of their battery production due to mining, the long charging time and, above all, the fact that 65% of the global electricity is generated by fossil fuels, the relevance of further developing internal combustion engines fueled with biofuels is unquestionable. Lately, the turbulent jet ignition (TJI) system has been intensively studied as a means to reduce specific fuel consumption (SFC) and pollutant emissions from engines. Both active and passive TJI are endowed with high ignition energy allowing the spark-ignited engine to run with lean mixtures and low covariance of IMEP.

In 2020, 3.6 million of heavy-duty vehicles operate in Brazil transporting 1,548 billion TKU goods and 2,372 million passengers every year. 45.1 billion of liters of Diesel are consumed per year emitting 185.3 million tons of CO2 to atmosphere. Transportation is one of largest sectors of society in CO2 emissions, being responsible of 8.6% of GHG. In Brazil, heavy vehicles predominantly are powered by fossil fuels. Huge efforts have been displayed by the scientific community to mitigate GHG emissions. Brazil has signed the term of COP 26 establishing a goal to reduce GHG emissions in 50% until 2030. Heavy duty vehicles are responsible of emitting 49.9% of CO2 of the transportation sector. The emissions standards of Brazilian legislations have decreased the limits of NOx, PM, CO in 75, 94 and 63% since 2000 were PROCONVE P2 have stabilized the first emissions limits for heavy-duty vehicles.

Direct inject engine provides increased possibilities to work with injection strategies in order to achieve better efficiency. Some ethanol properties such as the higher octane number, the latent heat of vaporization as well as the faster laminar speed made ethanol one of the most promising biofuels. These properties help to achieve knock suppression in a SI engine and therefore allow the use of higher volumetric compression ratio, which is one of the key factors in efficiency improvement. Several studies have showed ethanol as a way to reduce soot formation in direct injection engines as the oxygen molecule reduces the locally fuel-rich region. The use of ethanol contributes significantly to the reduction of total hydrocarbon (THC) and carbon monoxide (CO).

In the actual context, Researchers are making efforts for becoming mobility more sustainable. Whithin it context, the strategy of direct injection of renewable ethanol fuel in spark ignition engines is an interesting alternative for substitution of fossil fuels. In Brazil, the majory part of ethanol fuel production is provenient of sugar cane that has the potential to absorb great quantity of carbon dioxide through the photosynthesis process. The focus of this study was to create a very low computational cost methodology for evaluating the shape of sprays produced by an inwardly opening pressure-swirl injector. The referred injector is to be used in four stroke spark ignition engines for delivering fuel directly inside the combustion chamber. The spray geometry was then predicted by numerical calculations of single droplets trajectories in a purely lagrangian approach. The working fluid injected considered was EXXSOL D60.