« Overview of CAA techniques applied to various propulsion and cooling systems ».
ing., Ph. D. - Professeur agrégé - Université de Sherbrook
Lundi 29 Avril à 10 h 00
Noise reduction driven by more stringent specifications requires the introduction of acoustic predictions in the design process of many flow-moving machines. However, reproducing their noise spectrum especially for high-speed turbo-engines that contains both tonal and broadband components over a large range of frequencies may seem a daunting task. Two main Computational Aero-Acoustics approaches can be used to estimate noise. First, a hybrid method where the noise sources are computed accurately in a limited zone, the surface in wall-bounded cases, the shear region in free shear-layer flows and the far-field acoustic pressure is then obtained by an acoustical analogy. Secondly, direct noise computation can be performed using compressible turbulent simulations. The latter is still limited to basic flows at low Reynolds numbers, except maybe at low Mach numbers where the Lattice Boltzmann Method provides an efficient way to compute noise radiation of complex installed systems. Both paths are first illustrated on three canonical problems, airfoil self-noise, single-stream cold jet noise, and rotor-stator interaction, then on more complex systems such as low-speed fan noise and high-speed nozzle jet noise.