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Society sees itself in an era in which ecological and sustainability issues have assumed great importance, and with that, several issues need to be revised. When it comes to mobility, a key point is to determine the most efficient way to travel a certain distance with the lowest cost and environmental impact. Due to the size of the world fleet of vehicles, it is easy to understand how an increase of efficiency of the internal combustion engines (ICE) lead to a reduction of the total volume of fuel consumed in the planet. That combined to the possibility of integration with an online network, showing the flow conditions of each road, would allow a further reduction of the fuel consumed globally as well as a mitigation of the emission of harmful gases to the environment associated to urban mobility. In Brazil, the automobile fleet consists of approximately 60% of Flex-Fuel vehicles, which can use either ethanol or gasoline.

Brazilian energetic matrix is based on two fuels: gasoline (E22: 78% pure gasoline + 22% anhydrous ethanol) and ethanol (E100: 93% anhydrous ethanol + 7% water). A Flex Fuel 2-wheeler (motorcycle) engine management software strategy was developed in order to meet Brazilian market demand based on the energetic matrix mentioned above and a worldwide market forecast growth in the corresponding small engines segment. As 2-wheeler engine configuration and electric architecture is simpler than passenger cars, a premise was established: to develop a completely new Flex Fuel system for the 2-wheeler segment with functionalities simpler and easier to calibrate than actual concept used for Flex Fuel passenger cars. This paper presents the result of this study: a Flex Fuel system able to operate with gasoline (E22), ethanol (E100) or any mixture of both fuels with similar behavior in an easy-to-calibrate system.

Recently many government Acts (Inova Energia, Inovar-Auto, RenovaBio) [1, 2, 3] have been implemented in order to expand the use of biofuels in Brazil. Besides the fulfillment until 2030 of the commitment assumed at the COP21[4] to reduce in 43% the gas emission contributing to the greenhouse effect, the expansion of the use of biofuels is important to assure regularity in the supply of fuels to the automotive sector in the next 15 years. In this context, it is worth mentioning a special characteristic of the Flex-Fuel engines that equip the majority of the automobiles in Brazil since their launching in 2003. The maximum compression ratio of these engines depends on the knocking characteristics of the gasoline, but usually an intermediate value, nearer to the ideal value for gasoline, is a compromise.

It can be said that the greatest engineering challenge of mobility it is not related to the energy shortage, but to its generation and sustainable use. In this context, the growing use of biofuels by high performance internal combustion engines represents a sustainable alternative from the economic, technological, social and environmental point of view. In some regions of the planet, the modern electric and hybrid vehicles may not be the most sustainable choice, since they face many obstacles regarding clean energy generation, reduced recharging station network, limited autonomy, expensive vehicle prices, and battery recycling. In Brazil since its launching in 2003, the fleet of Flex-Fuel vehicles moved by either ethanol or gasoline is ever increasing. It is worth mentioning that the biofuel has physical and chemical properties that could make its use more efficient than it is nowadays.

The adoption of high compression ratios when designing an internal combustion engine is often used to improve thermal efficiency. However, compression ratio cannot be enhanced indefinitely since elevated pressures and temperatures inside the combustion chamber may cause knock. In view of this issue, it is important to have an accurate knowledge about the conditions in which the probability of knock occurrence is high to preserve engine integrity and achieve the best performance. In addition, if numerical tools are available for this type of analysis, time and experimentation costs can be avoided. Based on this idea, this paper presents a numerical tridimensional study of knock occurrence in a spark ignition three-cylinder engine operating with different compression ratios and late intake valve closing.

In some engine measuring systems, the signal acquisition is synchronized with crank angle, rather than time. This technique is particularly beneficial when dealing with parameters such as incylinder pressure and other combustion analysis data that are closely linked to the engine working cycle. In such system, the crankshaft’s top dead center triggers the start of an acquisition with periods of varying time duration, which depends on engine speed [1]. However, there are scenarios where these very signals must be analyzed along with signals acquired with time synchronization. This is the case, for example, of engine knocking calibration, in which combustion data should be linked with injection, ignition, and other engine parameters, which are time-based. Moreover, most used signal processing algorithms are conceived for uniform sampling.

In the Brazilian automotive market, the Flex Fuel vehicles are known for their ability to run with gasoline, ethanol, or any proportional mixture of them. To allow this flexibility, the vehicle’s fuel system has been adapted to support differences in fuel types available in the Brazilian market, including contaminated fuel that in this paper will be treated as aggressive ethanol. The fuel pump, which has the function of supply fuel to the engine, had to be specially developed for the flex fuel application to support the specific characteristics in Brazilian ethanol. The focus of this paper is to evaluate the influence of different fuels - gasoline, ethanol, and aggressive ethanol in the sparking level of the DC fuel pump commutation system. Using a digital oscilloscope, the voltage signals of the fuel pump were recorded, and it was applied a mathematical formulation to determine the sparking level of the DC motor for the different fuels.

Characteristics Multi-fuel vehicles demand great interest nowadays. This technology makes it possible for engine to work properly with any ethanol-gasoline mixture or Compressed Natural Gas (CNG). The preexisting spark plugs for either ethanol or gasoline engines have been created based on different functional requirements. On this context, to ensure a better performance in any mixed fuel-ratio and CNG high compression rate it was necessary to develop a spark plug taking into account the requirements for both cases simultaneously. The purpose of this paper is to enlighten the main technical spark plug features as enhanced thermal elasticity, improved ignition reliability through (Quick Heat™ design) and enhanced service life (less sooting, improved corrosion protection).