Publications
Titre : | Asymptotic modeling of boundary layers in aeroacoustics |
Année : | 2011 |
Type : | conférence internationale avec actes |
Auteurs : | A.-S. Bonnet-BenDhia, P. Joly, L. Joubert |
Résumé : | Taking into account the boundary shear layers of the mean ow in aeroacoustic compu- tations requires expensive mesh renements, the size " of the layer being small compared to the acoustic wavelength . On the other hand, neglecting these thin layers can reduce signicantly the accuracy of the simulation, and even worse, it can lead in case of absorb- ing walls to an ill-posed problem, intractable numerically. The solution that we propose consists in deriving a new boundary condition which takes into account at the rst order in "= the presence of the boundary layer. Well-posedness and stability of the new problem are studied by a modal analysis. The results depend on the Mach prole of the boundary layer and, for an impedant wall, on the values of the impedance model. For instance, the problem with a linear or parabolic prole is stable for the case of a rigid boundary, and unstable but well-posed for an impedant boundary with a large impedance Z. Numerical validations are in progress. |
Thèmes : |
Modèles asymptotiques Phénomènes couplés |
Référence : | - American Institute of Aeronautics and Astronautics |