High Efficiency Flex-Fuel Engines, the Route for Brazilian Mobility

Abstract

In order to mitigate the greenhouse gases emission from automobiles and to reduce the dependency on fossil fuels, various alternatives for replacing the internal combustion engine are available. However, the best solution for this dilemma must take into account the geographic and social-economic characteristics of the country, its energy matrix, its emission legislation, and the fuel carbon footprint during its entire lifecycle. Brazil has a strong reputation for its fleet of Flex-Fuel vehicles, long date experience in the use of ethanol fuel and its distribution network. This differentiates it from other global markets and justifies a unique approach for the CO2 emission reduction. This article describes a project with the main objective of optimizing the efficiency of Flex-Fuel engines running on ethanol, without deteriorating their performance with gasoline. The influence of the geometric compression ratio, the airflow structure and the inlet valve opening/closing strategy was investigated for fuel consumption and engine performance. The analysis of the experimental data confirmed the benefits of the compression ratio optimization on the combustion efficiency. Therefore, the development of efficient Flex-Fuel engines will lead to a sustainable route for mobility in Brazil.