Beam and plate-like structures with non-constant surface impedance are known to exhibit wavenumber scattering such that the wavenumber energy of a vibration mode of the structure is spread over a wide wavenumber band. The scattered energy can couple into partially-correlated forcing functions, such as turbulent boundary layer (TBL) flow, which exhibit a broadband wavenumber spectrum centered at the convective wavenumber. The overall effect is an increased amount of radiated noise for certain flow speeds. Recently, structures with embedded acoustic black holes (ABH) have shown good noise and vibration level reductions for point excitations. However, it will be shown that when excited by complex, partially-correlated forcing functions such as TBL flow, the wavenumber scattering caused by the power-law taper of the ABH can lead to increased radiated noise levels. The flow speed and wavenumber dependence of the TBL/ABH interactions will be presented using dimensional analysis.
|Original language||English (US)|
|Journal||Proceedings of Meetings on Acoustics|
|State||Published - 2019|
|Event||178th Meeting of the Acoustical Society of America, ASA 2019 - San Diego, United States|
Duration: Dec 2 2019 → Dec 6 2019
All Science Journal Classification (ASJC) codes
- Acoustics and Ultrasonics