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Computational tools have become indispensable in the development of cam profiles, aiding designers in achieving optimal performance. This paper explores the application of computational tools in the design of cam profiles for a single-cylinder research engine (SCRE) prototype under development with a direct-acting mechanism. The primary objective is to present a comprehensive design process, encompassing kinematic analysis and Quasi-Dynamic Analysis (QDA), to enable designers to generate preliminary cam profiles based on design requirements. The VT-Design® software, a part of the GT-SUITE package, is employed for simulations in this study. Key design considerations, such as lift, velocity, and acceleration curves, are discussed, emphasizing the importance of maintaining continuity in the acceleration curve. The design process involves optimizing the acceleration curve to minimize negative acceleration and improve dynamic response.

The use of green hydrogen as a fuel for internal combustion engines is a cleaner alternative to conventional fuels for the automotive industry. Hydrogen combustion produces only water vapor and nitrogen oxides, which can be avoided with ultra-lean operation, thus, eliminating carbon emissions, from a tank-to-wheel perspective. In this context, the aim of this study is to investigate the influence of hydrogen injection timing and duration on the homogeneity of the hydrogen-air mixtures. Computational fluid dynamic (CFD) simulations were performed to analyze the distribution of air-fuel ratios along the engine's combustion chamber. The simulation software was CONVERGE 3.0, which offers the advantage of automatic mesh generation, reducing the modeling efforts to adjusting the operating conditions of the studied case. Before comparing the injection parameters, a mesh independence test was conducted along with model validation using experimental data.

The development and improvement of efficient compressed natural gas (CNG) engines align with efforts to reduce greenhouse gas and pollutant emissions. The objective of this study is to evaluate the flame structure and compare the performance characteristics of an engine powered by compressed natural gas (CNG) under stoichiometric and lean combustion in wide open throttle. CFD simulation alongside experimental tests are performed. The experimental data were obtained using a Hyundai 2.5-liter HR engine, originally a Diesel engine, adapted for spark ignition operation. Lean and stoichiometric conditions were evaluated at compression ratio 14:1, operating at 1800 rpm in MBT spark timing. The results showed that increasing lambda (λ) had a significant effect on apparent heat release rate, laminar flame speed, flame thickness and flame surface area.

In order to further explore the potential of hydrogen as an alternative fuel, this study aims to validate a computational fluid dynamics model for hydrogen combustion in a port fuel injection spark ignition engine. The engine operates at 1800 rpm with a compression ratio of 10:1, under two lean combustion conditions: excess air ratios of 2.5 and 1.7, at full and part load, respectively. The simulations were performed using the CONVERGE 3.1 software and the C3MechV3.3 reaction mechanism. The predictions were then compared with experimental data to assess the accuracy and validity of the model, enabling the comparison of different lean operating conditions to evaluate important combustion characteristics, such as flame development, apparent heat release and NOx formation. The tested model successfully validated the two experimental conditions, accurately adjusting the in-cylinder pressure profiles for both cases of lean hydrogen mixture combustion.

The use of green hydrogen as a fuel is a promising solution for reducing greenhouse gas emissions from our current fleet of petrol-fueled vehicles. However, achieving zero emissions remains a challenge due to the higher relative air-to-fuel ratio (lambda) required to avoid NOx formation during periods of increased load demand. On the other hand, the capability of hydrogen combustion to use a lean mixture with lower combustion variability presents a great advantage. In such cases, thermal efficiency can be improved by reducing pumping work through leaning the mixture and dethrottling to maintain the same load. This study investigates the efficiency and combustion parameters of hydrogen spark ignition operation while maintaining a constant load at several intake pressure conditions. Tests were conducted on a Ricardo Proteus spark ignition single-cylinder research engine to evaluate the impact of throttle aperture on pumping work and combustion parameters.

The increasingly strict environmental legislations require the use of strategies and technologies to achieve higher efficiencies in internal combustion engines (ICE). In Brazil, governmental programs as Rota 2030 stimulate the development of technologies to improve engine efficiency and therefore promote fleet decarbonization. Due to lower carbon footprint, the use of renewable fuels as ethanol is an effective way to reduce greenhouse gas emissions. Nowadays, direct injection (DI) and variable valve timing (VVT) technologies are also used in modern downsized engines to reach higher thermal efficiencies with advanced strategies operation. As a significant part of energy losses in a spark ignition (SI) engine is caused by pumping work due to the method used for load control, operation in lean conditions have the potential to increase engine efficiency due to less pumping work requirement.

Increased energy demand and security of energy supply have become a concern in recent decades due to strong industrial growth. The high cost of fossil fuels and the need to reduce the emission of greenhouse gases have made renewable energy sources an attractive object. In this context, biomass becomes interesting and is the second largest source of renewable energy in Brazil, possessing many characteristics similar to fossil fuels. Energy can be obtained by direct burning or by conversion into biofuels, such as biogas, which is composed primarily of carbon dioxide and methane. Methane released directly into the atmosphere has 21 times the greenhouse effect potential of CO2. In this way the importance of the development and improvement of this fuel and of the converter machines, which play a fundamental role in the transformation of biomass into other forms of energy, is justified.

Fossil fuels are non-renewable resources of energy, being one of the largest fractions of the greenhouse gases (GHG). Hydrogen is indicated as a fuel with potential to replace fossil fuels in the future, mainly because the combustion products are environmentally friendly, with high specific energy, in comparison with other sources of fuel. However, to use hydrogen as a fuel in internal combustion engines (ICE) or in fuel cell vehicles (FCV), it is necessary to separate it from primary elements (water, biomass, natural gas, etc.). It´s also need to consider storage and transport in order to handle a fuel like hydrogen. All of these phases require energy, which may be from renewable or non-renewable sources, causing environmental impacts. In order to investigate if the hydrogen is economically viable, aspects such as environmental impacts, safety and technological feasibility need to be studied.

Wet ethanol is a low cost renewable fuel which often shows challenging ignition in spark-ignited engines. This can be tackled by using non-flame propagating combustion modes like HCCI. This paper shows experimental results of a diesel fueled generator set which recovers exhaust heat from one of the diesel cylinders to promote HCCI of ethanol on other cylinders. Experimental tests provided results of heat release, energy efficiency and a thorough combustion analysis that demonstrate the possibility of this concept which requires minimal changes on the original engine, making possible to retrofit existing units. A three-cylinder four-stroke engine originally fueled with diesel was used. The diesel injection system in one of the cylinders was replaced by an ethanol electronic fuel injection. Inlet heat for achieving HCCI was provided by complete exhaust recycling from one of the diesel cylinders. Stable HCCI combustion was achieved in the ethanol cylinder.

Reducing environmental pollution by the transport sector has been influenced according to the increasingly restrictions imposed by regulatory standards. For this, legislation such as Euro (at global level) and Proconve (at local level) set new limits each new phase, usually stipulating reductions in the levels of greenhouse gas emissions. Compliance with these requirements is seen with the vehicle or engine ratings working through the conditions imposed by a standard test cycle. However, standard driving conditions often do not represent the real-world driving conditions, being influenced by relief, traffic lights and other peculiarities of each city or route. This paper aims to compare real-world driving cycles of urban bus and passenger car in the city of Santa Maria, in southern Brazil, with the conditions used for light gasoline vehicles and heavy diesel vehicles approval.

This paper presents the design process of an aerodynamic kit for a Formula SAE competition vehicle using CFD with special attention to the distribution of aerodynamic loads. The methodology for the development of concepts is to create a boundary that respects the geometric constraints of the vehicle and also complies with FSAE 2015/16 Rules. Inside these boundaries different geometries of aerodynamic accessories can be analyzed and several full vehicle models can be created. The initial model is conceived based on the literature and then analyzed with CFD to generate another model. The process is repeated until it reaches a model that cannot be considered optimum but is close enough to the targets previously defined. The governing equations for the numerical simulation are presented as well as the reason for their use.

In order to improve urban air quality and to meet legislation requirements, vehicular technology is constantly advancing. It focuses on techniques that reduce fuel consumption and emissions of greenhouse gases as well as harmful pollutant emissions. The technologies, however, have different impacts depending on the city, its traffic conditions and urban planning as well as other socioeconomic and cultural factors that affect the driving stile. Thus, standard drive cycles such as NEDC, FTP75 and HWFET may not represent properly the actual condition and are being progressively replaced by real-world driving cycles. This paper aims to analyze real-world driving conditions in the city of Santa Maria, in southern Brazil, in respect to emissions and fuel consumption. Computer models were used to establish a comparison between standard conditions and real conditions, acquired experimentally by a family car.

Various studies previously conducted have estimated the net energy value for ethanol, but the variations of data and assumptions used caused the results to lack in precision. However, studies are unanimous in pointing out that the greatest fraction of the energy necessary for making ethanol is spent in water removal (distillation and dehydration), growing exponentially the smaller the amount of water in the final product. By using wet ethanol to avoid the energy cost of dehydration, the purposes of this work were to numerically evaluate the energy spent in the distillation process and compare the results with the efficiency in using wet ethanol as fuel. The simulation was modelled through Matlab® software environment, using as base a distillation column for batch process with a variable number of plates to obtain as a final product ethanol with different degrees of hydration.

Formula SAE racing engines must provide high output with maximum fuel efficiency despite the air restriction imposed by the rules. Throttle response and engine load control are very important due to the track characteristics with a few straights zones and many curves. In-cylinder pressure cyclic variations harm vehicle control and increase fuel consumption, due to the torque fluctuations. In order to reduce fuel consumption and improve vehicle drivability, engine calibration having the in-cylinder as a feedback parameter is an essential procedure and will be the focus of this paper. Test bench data with combustion analysis will be performed, using the COVIMEP as a combustion stability index. Tests were carried out on a motorcycle engine modified to run under the Formula SAE competition rules.

Zero-dimensional zonal models are seen as interesting tools for engine simulation due to their simplicity and yet accuracy in fitting or predicting experimental data. For combustion, a common model is a dual zone model, in which two-zones, spatially homogeneous, are set during the combustion process. Such model take into account an interface of infinitesimal thickness for the separation between zones. The success of this simulation approach depends on the accuracy of the heat transfer model. These models aim to obtain the heat transfer coefficient from the combustion gases in contact with the cylinder walls. Several heat transfer correlations from the literature can be used to obtain the heat transfer coefficient.

The ever increasing pressure for more efficient engines, with lower production cost and time has led to the development of advanced simulation tools. Likewise, the experimental development of combustion systems has benefited from computational tools while reducing the necessary experimental time. This paper describes the analysis of combustion performance of a Diesel engine normally used on generator sets. A detailed heat release analysis is performed through one-dimensional simulation software and experimental results, enabling a comprehensive description of combustion parameters of the engine through a simplified study. Brake and indicated values were obtained and analyzed to point out efficiency maps and show the effectiveness of the simulation tool in engine and combustion systems development.

Due to the ever growing environmental concern regarding global warming and CO₂ emissions, the use of renewable fuels has become increasingly important. Thus, substituting fossil fuels such as diesel by ethanol from sugar cane can be a good alternative. There are, however, several ways of performing it. One of the simplest methods is to use fumigated ethanol with an electronic fuel injection system, operating in dual fuel mode with the original diesel injection, substituting part of the fuel by ethanol. This paper demonstrates the effects of using fumigated ethanol on performance of a standard power generation 4-cylinder turbocharged diesel engine. The research combines simulation results with experimental validation. Initially, a one-dimensional computational model of the original engine running solely on diesel was created and validated for several power levels.