Simulation aux grandes échelles: instabilités thermo-acoustiques, combustion diphasique et couplages multi-physiques

Turbulent combustion, either in lab-configurations or real industrial ones, involves an important number of strongly coupled physics : chemistry, turbulence, multi-phase flow, heat transfer, etc. To answer the more and more challenging needs of engineers, who have to propose competitive solutions while respecting environmental constraints on noise and pollutant emission, numerical simulation has become a key factor. More precisely, simulation being now used as a design tool, must be reliable and accurate. In the domain of turbulent combustion, with strong unsteadiness, Large Eddy Simulation (LES) has recently become essential. This technique has proven to be able to predict with fine detail the behavior of burners in complex environments, and allows today to address problems that are not fully understood, such as thermo-acoustic instabilities or two-phase combustion. Some examples of such open problems are here given. Mots clefs : Turbulence ; Combustion ; Simulation