Aeroacoustic study of a submerged air inlet using an IDDES/FW-H approach and sound source modelling through numerical beamforming
2016 (English)In: 22nd AIAA/CEAS Aeroacoustics Conference, 2016Conference paper (Other academic)
The aerodynamic sound sources on a generic model of submerged air inlet are studied numerically at a low Mach number. The model of inlet is based on an experimental inlet developed by the National Advisory Committee for Aeronautics (NACA). The flow past the inlet is solved through detached eddy simulation, while the acoustic pressure in the far-field is estimated using a Ffowcs Williams and Hawkings integral. Aeroacoustic sources are then localized using a beamforming method, with an array of “microphones” within the computational domain to which sound is propagated directly. A linear programming deconvolution approach is used to improve the resolution of the beamform map. The analysis is performed at three velocity ratios, 0.4, 0.6 and 0.8, corresponding to the ratios between the velocity at the duct entrance and the velocity of the free stream. Results for the flow are compared with experimental results from NACA and show a very good agreement in terms of integral variables and local surface pressures. A transition is observed between a quasi-laminar flow at a high velocity ratio and a turbulent flow at lower velocity ratios. This behaviour at low velocity ratios is associated with much higher acoustic levels in the far-field, and with a broadband character of the sound, while the behaviour at high velocity ratios is associated with lower acoustic levels and a tonal character. The beamform map is expected to show acoustic sources on both sides of the lip, with high amplitude and broadband content for low velocity ratios, and a more tonal character for high velocity ratios.
Place, publisher, year, edition, pages
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-185034DOI: 10.2514/6.2016-2838OAI: oai:DiVA.org:kth-185034DiVA: diva2:918056
22nd AIAA/CEAS Aeroacoustics Conference, 30 May - 1 June 2016, Lyon, France
QC 201606132016-04-082016-04-082016-06-13Bibliographically approved