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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.

In order to reduce greenhouse gases and respect stringent pollutant emission regulations, the modern engine is increasingly required to incorporate energy recovery systems to enhance performance and increase efficiency. This paper deals with the exhaust energy recovery through turbocompounding. Both series and parallel turbocompounds are discussed. In the first part of the document, literature on turbocompounding is introduced. Then a simulation study carried on AMESim software, using a 2L Diesel engine model is presented. The parallel turbocompounding is simulated by expanding a part of the exhaust gases in a converging nozzle instead of the turbocharger turbine. The power produced is evaluated as a function of the pressure drop in case a turbine is mounted instead of the nozzle. A global study over the entire engine map is described, and two steady state points 2000 rpm, 8 bar and 3500 rpm, 7 bar are chosen.