Large-Eddy simulation of lean direct injection H2 combustion

With the reduction of hydrocarbon resources and increasingly stringent standards to deal with the problem of climate change, the development of clean-up internal combustion engines constitutes a major technical challenge. The use of hydrogen is considered a promising alternative for vehicles. Two main options are possible. The most studied is the fuel cell, which is particularly attractive for its potential efficiency and its emissions (only water vapour), but it is less advantageous in terms of cost and durability. Otherwise hydrogen introduced as a fuel in internal combustion engines has the advantage of benefiting from existing infrastructures and not depending on rare materials.
However, a certain number of technological obstacles remain to be overcome: which injection and mixing strategy to limit abnormal combustion and flashback? How to optimise the specific power? Which dilution strategy to reduce NOx emissions without penalising efficiency ? To answer these questions, the numerical simulation is a major asset.
The objective of the thesis is to develop and validate a 3D simulation methodology for the prediction and study of the mixture, the ignition phase and the propagation of an H2 / oxidiser flame by spark ignition engine to enable the specification of injection and ignition systems. This methodology will exploit the Large-Eddy Simulation (LES) to address in detail the formation of the H2/O2/diluent mixture and the interactions between the spark and aerodynamics, chemistry and turbulence, flame and walls. The impact of dilution on ignition and NOx emissions will also be explored.
Taking into account the innovative nature of the work, publications in high quality scientific journals are expected.

Keywords: spark ignition engine, turbulent reactive flows, hydrogen, modelling, Large-eddy simulation

• Academic supervisor    Dr Olivier COLIN, IFPEN
• Doctoral School    SMEMAG (ED 579), lien sur le site
• IFPEN supervisor    Dr Karine TRUFFIN, karine.truffin@ifpen.fr
• PhD location    IFP Energies nouvelles, Rueil-Malmaison, France  
• Duration and start date    3 years, starting preferably on October 1, 2019
• Employer    IFP Energies nouvelles, Rueil-Malmaison, France
• Academic requirements    MSc Fluid mechanics and/or Energetic
• Language requirements    Fluency in French or English, willingness to learn French
• Other requirements    Computational fluid mechanics, combustion, numerical methods and programming (C/C++ and Python), interest in the field of new energy technologies and turbulent combustion theory