Noise radiation in aerofoil flows: a global stability analysis
Event details
| Date | 13.11.2012 |
| Hour | 10:15 |
| Speaker | Miguel Fosas de Pando (LadHyX, CNRS - Ecole Polytechnique) |
| Location | |
| Category | Conferences - Seminars |
Even in low-turbulence environments, aerofoils can radiate substantial levels of noise from the sole interaction between the boundary layers and the wake: experiments show that for moderate-to-high Reynolds number and small angles of incidence, the sound spectrum is characterized by discrete tones that are commonly perceived as a whistle. The visualization of the flow reveals that the acoustic emission is correlated to the ringing of coherent structures near the trailing edge, suggesting a nontrivial interplay between acoustics and hydrodynamics.
Although this problem has received considerable attention since the 70's, a satisfactory explanation for the physical origins of the tones is still incomplete, mainly due to the intrinsic limitations of classical hydrodynamic stability theory for the analysis of long-distance feedback effects. In this presentation, we address the noise generation mechanism by means of linear global stability theory. The predictions from the linear analysis will be compared with nonlinear simulations and at that point, the outreach of a global linear study will be assessed.
Although this problem has received considerable attention since the 70's, a satisfactory explanation for the physical origins of the tones is still incomplete, mainly due to the intrinsic limitations of classical hydrodynamic stability theory for the analysis of long-distance feedback effects. In this presentation, we address the noise generation mechanism by means of linear global stability theory. The predictions from the linear analysis will be compared with nonlinear simulations and at that point, the outreach of a global linear study will be assessed.
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Practical information
- Informed public
- Free
- This event is internal
Organizer
- Prof François Gallaire
Contact
- Prof François Gallaire