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This paper presents a new firing concept for internal combustion engines called APIR and its performances. This concept attempts to merge the best of both Compression Ignition (CI) and Spark Ignition (SI) engine worlds. The application of this concept to a standard SI engine, leads to a consequent improvement of the firing and combustion performances. Initiation and combustion develop with a speed and a repeatability incomparable with the spark plug firing case. The use of the APIR device leads to an increase of the engine operating range in terms of lean operating limit and thus lean burn torque range. This paper points out that the APIR device has a lower knock sensitivity and isn't much affected by the in-cylinder aerodynamics. Thus, it can be shown that to take full advantage of the APIR concept in terms of efficiency and pollutants emissions, the SI engine must be redesigned in terms of compression ratio and in-cylinder aerodynamics.

This paper describes mid-load experimental tests combining massive EGR rates and multiple injection strategies. Influence of very high EGR rates on combustion has been reviewed, and a response-surface-modeling tool has been used to present main results. Outputs from this empirical model did highlight a dramatic soot increase when oxygen concentration is reduced. The empirical model based on experimental results model was also used to define more precisely the EGR rate needed to reach US 2010 NOx target. This EGR rate being defined, some investigation has been made on dual-injection strategies combining a main injection with an early pilot injection. Both quantity and timing of pilot injection were varied, and experimental results showed large benefits of this strategy to reduce soot emissions without significant increase of NOx emissions or fuel consumption. Better results were also experienced with the addition of a close post-injection.

This paper presents energy management strategies for a new hybrid pneumatic engine concept, which is specific by its configuration: It is not a vehicle but only an engine itself which is hybridized. This arrangement could provide as much as 30% of fuel saving depending on the driving cycle. Therefore different energy management strategies are proposed and compared in this paper. The first of them is called Causal Strategy and implements a rule-based control technique. A second strategy called Constant Penalty Coefficient is based on minimization of equivalent consumption, where the use of each energy source is formulated in a comparative unit. The balance between consumption of different energy source (chemical or pneumatic) is reached by introduction of an equivalence factor. The third strategy is called Variable Penalty Coefficient, where the equivalence factor is consider as variable within the amount of pneumatic energy stored in the air-tank.