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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.

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).