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Market expectations for the next generation of gasoline engines are: improved performance for better driveability, lower toxic emissions to meet future legislation, and reduced fuel consumption to help meet future legislation linked to Green House Gas emissions (including CO2) and to counter the recent increase in fuel price. In addition, any new technical solution must be cost effective and applicable to a large volume of engines. In order to improve fuel efficiency, the combustion process needs to be optimized. A key technology to achieve this is fully variable valve actuation for both naturally aspirated and turbocharged engines (variable displacement, reduced pumping losses, Miller-Atkinson cycles). To futher improve, accurate control of ignition and the air/fuel ratio will also be required and are necessary for CAI-HCCI combustion. VALEO Engine Management Systems has, since 1998, been working on an infinitely variable valve actuation system based on a linear spring-mass actuator.

Energy recovery of internal combustion engines has proved to be of primary interest to increase engine global efficiency. The motivation behind is to meet future fuel economy requirements and more stringent emissions regulations. Among all engine waste, research has shown that exhaust energy is the most promising solution due to its high availability. In this context, this paper deals with the analysis of the potential of exhaust heat recovery, especially by a turbocompound system. Turbo-compounding is already established in heavy-duty engines, in which an additional stage of expansion is made through an exhaust recovery turbine. This technique is now being studied for small displacement engines. In the first part of this document, a short history on turbocompounding is presented. Then we present a simulation study conducted on AMESim software, using a 0D 2L diesel engine model, calibrated to fit real engine test bench results.