Une méthode multiniveau pour la simulation des grandes échelles des écoulements turbulents compressibles

A multilevel method for Large-Eddy Simulation of turbulent unsteady compressible flows is proposed. It relies on the splitting of the turbulent flowfield into several frequency bands in space and time, each band being associated to a computational grid in physical space, allowing to take into account in a deterministic way the information contained on finer grids. A subgrid-scale model adapted to such a decomposition — based on a generalization of the Germano's identity to multilevel decomposition — is also introduced. The approach is validated by a simulation in a subsonic plane channel flow configuration.