日本航空宇宙学会関西支部分科会「流体力学における現代的アプローチ」講演会のご案内
- https://www.t.kyoto-u.ac.jp/ja/news-events/events/admg/20130701
- 日本航空宇宙学会関西支部分科会「流体力学における現代的アプローチ」講演会のご案内
- 2013-07-01T14:40:00+09:00
- 2013-07-01T15:40:00+09:00
- 日時 2013年07月01日 14時40分~15時40分
- 場所 京都大学 桂キャンパス C3棟 3階 b3n03室(航空宇宙工学専攻会議室)
- 連絡先 京都大学 航空宇宙工学専攻 高田 滋
- ウェブ http://gas.kuaero.kyoto-u.ac.jp/seminar2011-13/
Geometrical acoustics (ray acoustics) in applications to aeroacoustics
Dr. Takao Suzuki (Boeing, Seattle, USA)
(鈴木崇夫 博士,音響・流体力学技術部門,ボーイング社)
要旨:
Geometrical acoustics (i.e. ray acoustics) is a powerful tool providing insight into wave propagation in the high-frequency limit, where the acoustic wave-length is much shorter than the length scale of the medium (e.g. mean flow). By expanding the governing wave equation in terms of the frequency (or the wavenumber), the leading-order terms become the eikonal equation solving the ray trajectories, and the second leading-order terms the first-order transport equation solving the amplitude field. In the presence of velocity and temperature gradients in the mean flow together with a non-slip wall, waves of various types are created due to refraction, reflection, diffraction, and other phenomena. In this talk, derivation of the ray-tracing equations is first reviewed, and then applications of geometrical acoustics in high-speed flows are introduced. In particular, an application to a jet screech problem (shock associated noise) is discussed in addition to other types of waves, such as channeled waves and diffracted waves in the vicinity of a boundary layer.