The reduction of pollutant emissions in aircraft engines and power plants has become a major issue for gas turbine manufacturers as a result of more stringent environmental regulations and increased environmental concern. An efficient solution to reduce pollutant formation is to maintain a relatively low temperature in the combustor primary zone, by decreasing for instance the mixture equivalence ratio. The issue is that a low flame temperature induces slower chemical reaction rates often resulting in an increase of flame instabilities and extinctions. An emerging solution to enable flame stabilization in leaner regimes, suitable to a wide range of combustion applications, is to generate electrical discharges at the flame basis. Among these various types of discharges, the Nanosecond Repetitively Pulsed discharges have shown to beparticularly efficient. Despite this proven efficiency, the fundamental mechanisms of plasma-assisted combustion are not well understood. Also, the numerical tools needed by engineers to assess the performance of NRP discharge in practical configurations and optimize their design do not exist. The objective of this project is to elaborate and validate against experimental data a modeling route suitable to perform simulations of realistic turbulent combustion systems accounting for plasma-flame interactions. The discharge properties will be first characterized numerically and experimentally in a mixture representative of a combustor, which may contain fuel and recirculating burnt gases. These temporal and spatial distributions of species and temperature within the discharge will serve to calibrate a semi-empirical plasma-assisted combustion model recently developed. This model will be formulated in a LES context and implemented in an unstructured CFD solver. To build the validation database, experiments of plasma-assisted combustion will be conducted on two configurations: - The first one is a bluff body flame on which it has been already shown that the NRP discharge enables the flame stabilization over very lean regimes. The NRP discharge is efficient when located in small gases recirculation zone. We will perform complementary measurements on this configuration to characterize the composition and flow properties within the recirculation zone. - The second configuration is a swirled combustor representative of aeronautical combustion chambers. It is composed of a two-stage swirled injector and a rectangular combustion chamber with optical access ports. We will perform measurements to characterize the effect of the plasma on the flame stabilization process. It will be interesting to show that the plasma impacts significantly the stabilization mechanisms. The LES plasma-assisted combustion model will be applied to both bluff-body flames and swirled combustor configuration. Finally, we will perform the LES of a practical Lean Premixed Turbomeca combustor stabilized by NRP discharges as a project final big challenge.