Search Results

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.

The analysis of the air motion inside the cylinders of an internal combustion engine constitutes a very important step during engines design. It is already known that its movement, normally decomposed in tumble and swirl motion, is totally related to the majority of phenomena which occur inside cylinder, like fuel evaporation, mixture formation or flame propagation. The use of mechanical devices in the intake system represents an interesting option in the attempt of optimizing the airflow and finding the best condition for maximum power and minimum specific fuel consumption. Devices like flow boxes, which control the airflow and change its main characteristics before entering the cylinder, by obstructing the air and changing its directions, are one possibility. Based on this idea, this paper presents a numerical analysis of the utilization of a flow box in the intake system of a spark ignition engine.

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.