| タイトル | Viscous theory of surface noise interaction phenomena |
| 本文（外部サイト） | http://hdl.handle.net/2060/19800024668 |
| 著者（英） | Yates, J. E. |
| 著者所属（英） | Aeronautical Research Associates of Princeton, Inc. |
| 発行日 | 1980-09-01 |
| 言語 | eng |
| 内容記述 | A viscous linear surface noise interaction problem is formulated that includes noise production by an oscillating surface, turbulent or vortical interaction with a surface, and scattering of sound by a surface. The importance of viscosity in establishing uniqueness of solution and partitioning of energy into acoustic and vortical modes is discussed. The results of inviscid two dimensional airfoil theory are used to examine the interactive noise problem in the limit of high reduced frequency and small Helmholtz number. It is shown that in the case of vortex interaction with a surface, the noise produced with the full Kutta condition is 3 dB less than the no Kutta condition result. The results of a study of an airfoil oscillating in a medium at rest are discussed. It is concluded that viscosity can be a controlling factor in analyses and experiments of surface noise interaction phenomena and that the effect of edge bluntness as well as viscosity must be included in the problem formulation to correctly calculate the interactive noise. |
| NASA分類 | ACOUSTICS |
| レポートNO | 80N33176
ARAP-419
NASA-CR-3331 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/171133 |
