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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.

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.

Facing the stringent constraints on fuel consumption and pollutant emissions, the automotive manufacturers have to produce vehicles with an increasing number of complex systems working together. Numerical simulation for the system design, set-up and control strategies, helps to reduce the development cycle and the global cost. Existing simulation tools usually do not address, with a high level of details, the various physical domains involved in a vehicle powertrain. To overcome this challenge, IFP and IMAGINE, settled a partnership to develop detailed simulation tools dedicated to performance, consumption and emissions for conventional and hybrid vehicles [1]. These tools are integrated in a multi-domain simulation platform (AMESim®) where several levels of detail can be easily reached for each sub-element.

Today's engine development concentrates mostly on steady state conditions to benchmark performance. In fact, the engine behaviour under transient operation is increasingly of interest due to the dynamic interactions between the engine sub-systems. Transient testing is however highly demanding and requires complex and sophisticated facilities. This paper highlights an efficient way to investigate the transient engine behaviour using an original numerical approach based on the coupling between IFP-ENGINE, a 1D engine simulation tool, and IFP-C3D, a 3D combustion code. IFP-C3D is employed to extend or replace the experimental combustion maps used in IFP-ENGINE in the form of Wiebe's law. Basically, the process consists in first making the 3D in-cylinder combustion computations corresponding to all relevant engine operating conditions and then processing the combustion results via IFP-Combustion-Fitting, a specific tool that feeds IFP-ENGINE model with optimised Wiebe's law coefficients.

One of the most environmental problems nowadays is the reduction of the global CO2 emissions. In the field of automotive transportation, car manufacturers in Europe plan to reach the level of 140 g(CO2)/km in 2008) [1]. At this level, one of the most viewable solution is the use of lean-burn engines. This kind of engines are known for their combustion efficiency, but they present a major inconvenience: NOx emissions and their post-treatment. Some technical solutions have been provided in the past years such as DeNOx catalysts. However these solutions won't be compatible with future European legislations: limits of diesel engine emissions will reach 0.25 g(NOx)/km in 2005. One possible technology to overcome - such severe limits - is the NOx trap catalyst proposed by TOYOTA [2], which is already used by some car manufacturers on serial vehicles (such as PSA [3] and VW [4]).

The present research focuses on the understanding and improved prediction of knock at full load in a four-cylinder passenger car spark-ignition (SI) engine using computational fluid dynamics (CFD) methodology. The emphasis is on the possibility of controlling the knock limit via optimised engine cooling mechanisms. To date, CFD simulations of the combustion chamber and cooling circuit are performed separately, while chamber wall temperatures are derived from either experiments or experience. This, however, entails the risk of employing inadequate boundary and hence in-cylinder conditions for a combustion and knock simulation. CFD simulations are performed for all four combustion chambers and metal components, including the cooling circuit. Both types of simulations are thermally coupled via the conditions on the chamber walls.