Acoustic Resonances in a High Lift Configuration
Hein, Stefan and Hohage, Thorsten and Koch, Werner and Schöberl, Joachim (2007) Acoustic Resonances in a High Lift Configuration. Journal of Fluid Mechanics, 582, pp. 179-202. Cambridge University Press. ISSN 0022-1120.
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Low- and high-frequency acoustic resonances are computed numerically via a high-order finite element code for a generic two-dimensional high lift configuration with a leading edge slat. Zero mean flow is assumed approximating the low Mach number situation at aircraft landing and approach. To avoid unphysical reflections at the boundaries of the truncated computational domain perfectly matched layer absorbing boundary conditions are implemented in the form of the complex scaling method of atomic and molecular physics. It is shown that two types of resonances exist: resonances of surface waves which scale with the total airfoil length and longitudinal cavity-type resonances which scale with the slat cove length. Minima exist in the temporal decay rate which can be associated with the slat cove resonances and depend on the slat cove geometry. All resonances are damped due to radiation losses. However, if coherent noise sources exist, as observed in low Reynolds number experiments, these sources can be enhanced acoustically by the above resonances if the source frequency is close to a resonant frequency.
|Title:||Acoustic Resonances in a High Lift Configuration|
|Journal or Publication Title:||Journal of Fluid Mechanics|
|In Open Access:||No|
|In ISI Web of Science:||Yes|
|Page Range:||pp. 179-202|
|Publisher:||Cambridge University Press|
|Keywords:||acoustic resonances, aircraft high lift configuration, perfectly matched layer (PML), surface waves, slat cove resonances|
|HGF - Research field:||Aeronautics, Space and Transport|
|HGF - Program:||Aeronautics|
|HGF - Program Themes:||L AR - Aircraft Research|
|DLR - Research area:||Aeronautics|
|DLR - Program:||L AR - Aircraft Research|
|DLR - Research theme (Project):||L - Flight Physics|
|Institutes and Institutions:||Institute of Aerodynamics and Flow Technology > Helicopters|
|Deposited By:||Dr.-Ing. Stefan Hein|
|Deposited On:||22 Jun 2007|
|Last Modified:||08 Apr 2010 14:15|
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