Theoretical and numerical studies of sound propagation in low-Mach-number duct flows
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
When sound waves propagate in a duct in the presence of turbulent flow, turbulent mixing can cause attenuation of the sound waves extra to that caused by the viscothermal effects. Experiments show that compared to the viscothermal effects, this turbulent absorption becomes the dominant contribution to the sound attenuation at sufficiently low frequencies. The mechanism of this turbulent absorption is attributed to the turbulent stress and the turbulent heat transfer acting on the coherent perturbations (including the sound waves) near the duct wall, i.e. sound-turbulence interaction.
The purpose of the current investigation is to understand the mechanism of the sound-turbulence interaction in low-Mach-number internal flows by theoretical modeling and numerical simulations. The turbulence absorption can be modeled through perturbation turbulent Reynolds stresses and perturbation turbulent heat flux in the linearized perturbation equations. In this thesis, the linearized perturbation equations are reviewed, and different models for the turbulent absorption of the sound waves are investigated. A new non–equilibrium model for the perturbation turbulent Reynolds stress is also proposed. The proposed model is validated by comparing with experimental data from the literature, and with the data from Direct Numerical Simulations (DNS) of pulsating turbulent channel flow. Good agreement is observed.
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. , viii, 82 p.
TRITA-AVE, ISSN 1651-7660 ; 2015:30
Aeroacoustics, Acoustic wave absorption, Acoustic wave propagation, Boundary layer turbulence, DNS
Fluid Mechanics and Acoustics
Research subject Engineering Mechanics
IdentifiersURN: urn:nbn:se:kth:diva-168031ISBN: 978-91-7595-621-3OAI: oai:DiVA.org:kth-168031DiVA: diva2:814017
2015-06-15, D2, Lindstedtsvägen 5, KTH, Stockholm, 10:00 (English)
Åbom, Mats, ProfessorBoij, Susann, DocentHanifi, Ardeshir
FunderSwedish Research Council
QC 201505262015-05-262015-05-252015-05-26Bibliographically approved
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