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Rapid Compression Machine (RCM) is an experimental tool developed to study engine combustion parameters. The RCM used is a pneumatically and hydraulically driven device which reproduces a single combustion shot, considering a compression and a partial expansion stroke. This paper describes RCM adaptations made in order to run Otto cycle tests using Brazilian regular gasoline (E25) [1]. These adaptations enable pre-vaporized air-fuel mixture combustion tests, representative of port fuel injection engines, by using a gasoline direct injection (GDI) injector. It is also presented RCM piston displacement and cylinder pressure comparisons to a real engine and RCM comparative results for different spark timings and compression ratios. These results show that RCM reproduced satisfactorily piston displacement and pressure curves during the combustion shots, when compared to real engine curves.

Currently, fuels development is strongly dependent on experiments. New engines and vehicles simulation methodologies contribute to speed up R & D projects deadlines, as well as reducing costs. This paper presents a modeling methodology for a vehicle deceleration load curve (coast down) prediction and simulations of coast down variations impact on urban and highway autonomies. Two coast down curve mathematical models were successfully developed and validated. The first one, based on vehicles technical specifications and empirical equations, resulted in percent differences up to 9% compared to the experimental results. This is lower than the variation established on coast down standard, which is 15%. The second, generated by regression analysis between other vehicles characteristics versus experimental results of F0 and F2 (coast down curve parameters), resulted in percent differences up to 15%, for six of the eight vehicles.

Regarding fuels research and development, some preliminary studies - low cost and short time - can be conducted before the traditional engine tests - more expensive and time consuming. Therefore, experimental apparatus, such as a rapid compression machine (RCM) and specific methodologies, such as imaging techniques, are very useful in order to simulate engine combustion with simplicity, agility and flexibility, reducing development time and costs. Imaging techniques allow flame front propagation and ignition delay analysis, which are important parameters to understand fuel performance in engines and also to improve fuel modeling in engine simulation softwares. A RCM was adapted to operate in a spark ignition engine mode. It was used to obtain high-speed photos of flame propagation and ignition delay. Contour plots of the flame front profiles were obtained in successive frames to analyze the flame development with gasoline-ethanol blends.