Related references
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Article
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Summary: This study experimentally explores the effect of Mach number on airfoil tonal noise generation, finding that it has a significant impact on the frequencies and frequency intervals of the separation bubble and vortex shedding process under different angles of attack, while the dependence of tonal noise level on details of the laminar separation bubble and vortex shedding process is more complex.
Article
Physics, Fluids & Plasmas
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Mechanics
S. Probsting et al.
Summary: This study investigates the feedback effect of trailing edge sound on instability waves and the flow response to deterministic noise emissions on airfoils. Controlled acoustic perturbations are found to amplify shear layer perturbations in the separation bubble, leading to a transient reduction in the separation bubble size.
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Mechanics
Y. Yang et al.
Summary: Synchronized velocity and noise measurements on a NACA 0012 airfoil reveal the development of separated shear layer, vortex roll-up, and vortex breakup near the airfoil trailing edge, with specific peak structures in velocity fluctuations and noise spectra. POD analysis identifies energetic modes representing global flow field structures, aiding in understanding the mechanism of trailing edge noise generation. High amplitude noise emission is dominated by out-of-phase vortex shedding, while low amplitude noise emission is dominated by in-phase vortex shedding.
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