Acoustic Radiation from High-Speed Turbulent Boundary Layers in a Tunnel-Like Environment
Direct numerical simulation (DNS) of acoustic radiation in a double-wall (channel) configuration with two independent, spatially evolving flat-plate turbulent boundary layers is conducted under the flow conditions corresponding to those at the nozzle exit of the Boeing/AFOSR Mach-6 Quiet Tunnel (BAM6QT) operated under noisy-flow runs. The emphasis is on comparing the freestream pressure fluctuations in a geometrically confined environment with those radiated from a single flat wall in an unconfined setting. The DNS data shows that the acoustic fluctuations dominate in the core region of the channel. The acoustic radiation from the two different channel walls superimposes with each other, resulting in an intensity of the acoustic fluctuations approximately twice of that radiated from a single wall. The simulation is consistent with the observations by Laufer1 who found that the acoustic fluctuations radiated from different tunnel walls can be superimposed and the intensity of pressure fluctuations in the core region of the tunnel test section is approx- imately equal to that radiated from a single tunnel-wall boundary layer multiplied by the number of radiating boundary layers.
C. Zhang and L. Duan, "Acoustic Radiation from High-Speed Turbulent Boundary Layers in a Tunnel-Like Environment," Proceedings of the 53rd AIAA Aerospace Sciences Meeting (2015, Kissimmee, FL), American Institute of Aeronautics and Astronautics (AIAA), Jan 2015.
The definitive version is available at http://dx.doi.org/10.2514/6.2015-0836
53rd AIAA Aerospace Sciences Meeting (2015: Jan. 5-9, Kissimmee, FL)
Mechanical and Aerospace Engineering
Center for High Performance Computing Research
Keywords and Phrases
Acoustic Emissions; Acoustic Radiators; Acoustic Wave Propagation; Acoustic Wave Transmission; Acoustic Wave Velocity; Acoustic Waves; Aerospace Engineering; Atmospheric Thermodynamics; Boundary Layer Flow; Computational Fluid Dynamics; Turbulence; Turbulent Flow; Acoustic Fluctuations; Acoustic Radiation; Channel Wall; Confined Environment; Flow Condition; Freestream Pressure; Pressure Fluctuation; Turbulent Boundary Layers; Boundary Layers
International Standard Book Number (ISBN)
Article - Conference proceedings
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