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This paper analyzes the potential of a Fully Variable Camshaft Timing (FVCT) system for optimizing the performance of a highly boosted downsized ethanol SIDI engine running at high loads and reducing the emissions of pollutant gases. The FVCT influences the gas exchange process, which in turn modifies the charge composition and the cylinder filling. In order to achieve higher fuel conversion efficiency in conjunction with better emission levels, a FVCT strategy was defined seeking to characterize the best scavenging behavior. For all engine test conditions, the results showed that the FVCT adjusted to 5° before top dead center (BTDC) provided the lowest specific fuel consumption and, consequently, the greatest fuel conversion efficiency, despite the highest cyclic variability achieved.

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 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.