In the context of reducing pollutant emissions and diversify fuel sources, the CICCO project (Compression Ignition Combustion Controlled by Ozone) aims at studying the potential of modifying air oxidizing properties by ozone addition in compression ignition engine. Indeed thanks to its oxidizing properties, ozone significantly lowers the auto-ignition temperature of fuels, including those with low Cetane number. Thus, in the case of direct injection engines (diesel engine), ozone injection at the intake would improve the critical phases of start or restart. It would also allow to adapt the fuel to the compression ratio, or to reduce the compression ratio to lower pollutant emissions directly at the source. In the case of HCCI or LTC combustion, ozone injection would enable to control cycle to cycle the ignition temperature of the fuel-air mixture and therefore enhance the ability to control engine combustion. An actuator prototype will be realized and used from the beginning of the program to demonstrate the concept of combustion controlled by ozone. This prototype will meet the criteria of energy cost and controllability. The characterization of chemical species formed during discharge (O3, O, OH, NO ...) and can occur during fuel oxidation will be studied. The effect of ozone will be analyzed on two single cylinder engines without optical or with optical access for measuring chemiluminescence and fluorescence (LIF) of the OH * radical, OH and formaldehyde. Its impact on advanced combustion modes like HCCI type will be well characterized in a first indirect injection engine. The potential of ozone addition in a standard late injection diesel engines will also be studied on a diesel optical engine. To address fuel diversification, the influence of ozone on different fuels with low Cetane value (fuel such as petrol, bio-fuel, gas, refinery intermediates between gasoline and Diesel ...) will also be studied. In parallel, the existing EADF model for 3D simulation of diesel combustion will be extended to take into account the presence of ozone in fresh gas, and will be used to carry out RANS simulations of the different engines used for experimental studies. These simulations will improve the understanding of fuel oxidation by ozone, capitalize the experimental results and identify new injection strategies, dilution and use of fuels. Finally, from the experimental and numerical results, the most promising engine adjustments will be made on a single cylinder research engine running on stabilized and transient operating points. An optimized ozonizer prototype will be used to demonstrate the feasibility to control the cycle to cycle combustion a compression ignition engine with a factory-made device.

Gasoline direct injection (GDI) is among the technologies with a strong potential for improving the efficiency of spark-ignition engines. Considering the evolution of pollutant regulations, transient phases will play an increasingly critical role, and recent research has shown that transient phases are responsible for high particulate emission levels of GDI engines. The exact reasons of this observation are poorly understood, and classical design techniques that have proved their adequacy for optimising stabilized GDI operating points do not allow mastering these issues. In this context the objective of ASTRIDE is to contribute to a better understanding of the mixture preparation and the formation of liquid films during cold transients of internal combustion, gasoline direct injection (GDI) engines. Recent work has indeed shown that transients are responsible for important levels of soot particle emissions in such engines. The reasons for this are poorly understood, and classical design techniques having proven their adequacy for optimising stabilized operation of GDI engines fail to master them. The highly innovative work proposed by ASTRIDE is based on a combined usage of experimental techniques and Large-Eddy Simulation (LES) for studying transients in a single cylinder GDI engine, in a breakthrough approach as compared to classical techniques. This work will in particular profit from the innovative development of an analysis method of fast PIV velocity measurements for quantifying transient aerodynamics, and of a LES methodology for engine transients. This will be supported by experimental and modelling work concerning the characterization of sprays generated by last generation multi-hole injectors, their impact on a wall, the formation and evolution of a film, as well as of the evaporation of a film in a simplified configuration representative of the GDI context. The thus acquired understanding of the specificities of interactions between in-cylinder aerodynamics and the spray in GDI transients, and of their impact on the film formation and evolution, will be capitalised in the form of models for system simulation. The work proposed by ASTRIDE hereby aims at developing and validating breakthrough design tools that could contribute after the project to the emergence of GDI engines exhibiting soot particle production levels inside the cylinder that would be sufficiently low in order to avoid the negative impact in terms of cost and efficiency generated by the usage of soot particle filters in the exhaust.

The Triptic-H project aims to develop an aftertreatment solution for particulate emissions from stoichiometric spark ignition engines with direct fuel injection in connection with electrically hybridized vehicle applications. This type of engine is now known to emit a very large number of particles, mainly in the preferred modes of the hybrid application. The project anticipates the need of a treatment of these particles to reach the levels concerning the particulate number that will be required for the Euro 7 step. Moreover, this normative step will rely on a new test cycle more demanding than the current European test cycle NEDC, since it will be more transitory and covering an extended operating range. To achieve the objective of the project, a consortium is built, bringing together major players in the field of automotive manufacturing, of catalysis and of filtration of exhaust gases from combustion engines for automobiles, and of evaluation and optimization of engine / aftertreatment coupled systems. Two main technologies need to be explored to ensure the achievement of the objective assigned. The first complements a three-way catalyst and aims a high filtration efficiency, particularly for very fine particles, and the continuous oxidation of particles in gas containing small amounts of oxygen through a catalyst without precious metals. The second targets the simultaneous and synergistic treatment of particulate and gaseous emissions, within a single brick thus facilitating its integration in the vehicle. The project structure first aims to precise the knowledge of emissions to be treated through the use of advanced techniques of characterisation, then the joint development of innovative filter substrates and innovative catalytic phases tailored to the specific particles and gases identified. Core size prototypes will be manufactured and evaluated first at a laboratory scale, then full-size samples will be made for the most relevant solutions and evaluated coupled to an engine. Dedicated engine control strategies will lastly be developped to promote the continuous oxidation with no soot loading in the filter.