Turbulent boundary layer noise : direct radiation at Mach number 0.5
Article dans une revue avec comité de lecture
Date
2013Journal
Journal of Fluid MechanicsAbstract
Boundary layers constitute a fundamental source of aerodynamic noise. A turbulent boundary layer over a plane wall can provide an indirect contribution to the noise by exciting the structure, and a direct noise contribution. The latter part can play a significant role even if its intensity is very low, explaining why it is hardly measured unambiguously. In the present study, the aerodynamic noise generated by a spatially developing turbulent boundary layer is computed directly by solving the compressible Navier-Stokes equations. This numerical experiment aims at giving some insight into the noise radiation characteristics. The acoustic wavefronts have a large wavelength and are oriented in the direction opposite to the flow. Their amplitude is only 0.7 % of the aerodynamic pressure for a flat-plate flow at Mach 0.5. The particular directivity is mainly explained by convection effects by the mean flow, giving an indication about the compactness of the sources. These vortical events correspond to low-frequencies, and have thus a large life time. They cannot be directly associated with the main structures populating the boundary layer such as hairpin or horseshoe vortices. The analysis of the wall pressure can provide a picture of the flow in the frequency-wavenumber space. The main features of wall pressure beneath a turbulent boundary layer as described in the literature are well reproduced. The acoustic domain, corresponding to supersonic wavenumbers, is detectable but can hardly be separated from the convective ridge at this relatively high speed. This is also due to the low frequencies of sound emission as noted previously.
Files in this item
- Name:
- DYNFLUID_JFM_2013_GLOERFELT.pdf
- Size:
- 3.206Mb
- Format:
- Description:
- document article post-print
Collections
Related items
Showing items related by title, author, creator and subject.
-
Sparse Bayesian Learning of Explicit Algebraic Reynolds-Stress models for turbulent separated flows Article dans une revue avec comité de lectureA novel Sparse Bayesian Learning (SBL) framework is introduced for generating parsimonious stochastic algebraic stress closures for the Reynolds-Averaged Navier–Stokes (RANS) equations from high-fidelity data. The models ...
-
Article dans une revue avec comité de lectureAeroacoustic problems are often multi-scale and a zonal refinement technique is thus desirable to reduce computational effort while preserving low dissipation and low dispersion errors from the numerical scheme. For that ...
-
Article dans une revue avec comité de lectureAUBARD, Guillaume; STEFANIN VOLPIANI, Pedro; ROBINET, Jean-Christophe; GLOERFELT, Xavier (Springer Verlag (Germany), 2013)Explicitly filtered large-eddy simulations (LES), combining high-accuracy schemes with the use of a selective filtering without adding an explicit subgrid-scales (SGS) model, are carried out for the Taylor-Green-vortex and ...
-
Article dans une revue avec comité de lectureThis work is dedicated to the presentation of a matrix-free method for global linear stability analysis in geometries composed of multi-connected rectangular subdomains. An Arnoldi technique using snapshots in subdomains ...
-
Article dans une revue avec comité de lectureSONG, Ge; ALIZARD, Frédéric; ROBINET, Jean-Christophe; GLOERFELT, Xavier (American Institute of Physics, 2013)It is now well established that linear and nonlinear instability waves play a significant role in the noise generation process for a wide variety of shear flows such as jets or mixing layers. In that context, the problem ...