INFLUENCE OF THE NOZZLE-EXIT BOUNDARY-LAYER THICKNESS ON THE NOISE PRODUCED BY SUBSONIC IMPINGING JETS - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2023

INFLUENCE OF THE NOZZLE-EXIT BOUNDARY-LAYER THICKNESS ON THE NOISE PRODUCED BY SUBSONIC IMPINGING JETS

Résumé

The influence of the nozzle-exit boundary-layer thickness on the noise produced by initially laminar subsonic impinging jets is investigated using large-eddy simulations. For that purpose, six round jets at Mach numbers of 0.6 or 0.9, with nozzle-exit boundary-layer thickness equal to 0.05r 0 , 0.1r 0 or 0.2r 0 , where r 0 is the pipe-nozzle radius, are considered. They impinge on a plate located at 6r 0 from the nozzle-exit plane. For the jets at a Mach number of 0.9, the near-nozzle pressure spectra exhibit tones, at similar frequencies in all cases. However, for a thicker boundary layer, the dominant tone is nearly 30 dB stronger. The gain in amplitude of the shear-layer instability waves developing at its frequency between the nozzle and the plate also increases for thicker boundary layers. This indicates that the rise of the peak amplitude is the result of a higher amplification of the shear-layer instability waves. For the jets at a Mach number of 0.6, a large low-frequency hump and weak narrow peaks are found in the near-nozzle pressure spectrum for the thickest boundary layers, while no peaks are observed in the other cases. This suggests that impinging jets at Mach number lower than 0.65 can become resonant as their boundary layers are thicker.
Fichier principal
Vignette du fichier
Vincent_FA2023.pdf (4.08 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-04402197 , version 1 (18-01-2024)

Identifiants

Citer

Hugo Vincent, Christophe Bogey. INFLUENCE OF THE NOZZLE-EXIT BOUNDARY-LAYER THICKNESS ON THE NOISE PRODUCED BY SUBSONIC IMPINGING JETS. 10th Convention of the European Acoustics Association (Forum Acusticum 2023), Sep 2023, Turin, Italy. pp.5981-5988, ⟨10.61782/fa.2023.0335⟩. ⟨hal-04402197⟩
18 Consultations
8 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More