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Ensuigata-Rappa no Onkyogakutekino Seisitu ni tuite. (Sono 2.) : Tyoten ni Oto no Minamoto ga aru ensuigatano Rappa ni yoru Oto no Ba ni tuite.
https://jaxa.repo.nii.ac.jp/records/35329
https://jaxa.repo.nii.ac.jp/records/353295564eb8d-9bee-4e5e-a8f2-d7a12c9f9c51
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
SA4146504.pdf (749.3 kB)
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| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||||
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| 公開日 | 2015-03-26 | |||||||
| タイトル | ||||||||
| タイトル | Ensuigata-Rappa no Onkyogakutekino Seisitu ni tuite. (Sono 2.) : Tyoten ni Oto no Minamoto ga aru ensuigatano Rappa ni yoru Oto no Ba ni tuite. | |||||||
| 言語 | ||||||||
| 言語 | jpn | |||||||
| 資源タイプ | ||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||||
| 資源タイプ | departmental bulletin paper | |||||||
| その他のタイトル（英） | ||||||||
| その他のタイトル | On the Acoustical Properties of Conical Horns. (Part II.) : On the Sound Field due to a Conical Horn with a Source at its Vcrtex. | |||||||
| 著者 |
SATO, Kozi
× SATO, Kozi
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| 出版者 | ||||||||
| 出版者 | 東京帝國大學航空研究所 | |||||||
| 出版者（英） | ||||||||
| 出版者 | Aeronautical Research Institute, Tokyo Imperial University | |||||||
| 書誌情報 |
東京帝國大學航空研究所報告 en : Report of Aeronautical Research Institute, Tokyo Imperial University 巻 5, 号 64, p. 261-285, 発行日 1930-11 |
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| 抄録（英） | ||||||||
| 内容記述タイプ | Other | |||||||
| 内容記述 | The sound field due to a conical horn with a simple source at its vertex was calculated. If the origin is taken at the vertex of the cone and the polar axis on its axis, the velocity potential (φ) at any point (γ, θ) external to the horn is given by the following expression: -[numerical formula], where k=2π/λ(λ=wave-length), [numerical formula], μ_0=cosα, [numerical formula], [numerical formula], and a, 2α are the length and the angle of the cone respectively. From the above expression, we can calculate the energies at any point. The kinetic and potential energies have different values in general, but at an infinite distance from the source, they become equal and are inversely proportional to the square of the distance as in the case of a spherical wave. The results of numerical calculation for different values of ka are given in Figs. 1-6, where the kinetic energy at the distance indicated is protted as functions of θ in polar diagrams. The curves in each figure differ according to the distance γ. The above theory started with the assumption that on the spherical surface (γ=a) containing the opening of the conical horn, the motion of air exists in its opening only. The next investigation aims to compare the results of this theory with actual measurements. As the source of sound, Edelmann's metallic pipe was blown under a constant pressure with the aid of a carefully designed pseumatic tank. Fig. 7 (Du 7 on the page 276) shows the distributions of intensity in different directions, set at various pitches of sound produced by the pipe. As seen from the figure, the metallic pipe is different from a simple source of sound, the potential of which is given by e^<ik(ct-γ)>/γ, but within a small range of its front portion, it may be treated practically as such. At first, I tried to connect the source with the conical horn at its vertex, but in vain, for the pitch of sound changed considerably by such a connection. Consequently I made use of the reciprocal theorem, and put the measuring apparatus at the vertex of the cone, to receive the sound of the source put at different positions. The conical horn has an opening of 15cm. diameter and its angle is sixty degrees (α=30°). It is made to rotate horisontally with the vertex as center. The sound received through the cone is conducted by a metallic tube to a Rayleigh disc (see Du 8 on the page 277) and its intensity is measured. The experiments were made in a sound-proof chamber. Fig. 9 (Du 9 on the page 278) shows the results of experiments for)=16.6cm. The distances between the vertex and the source (γ) are 4λ, 6λ, and 10λ respectively. In the same figure, the intensity of sound received is shown in polar diagrams as function of the angle between the axis of the cone and the line connecting the source with the vertex of the cone. The curves in full and dotted lines are the results of observation and the theory respectively. In the case of γ=4λ, the experimental values are smaller than the theoretical ones in all directions. It is due to a sensible deviation of the source from a simple source, which become notable when γ is not large as compared to the length of the cone. When γ is large as compared to the length of the cone, its effect is negligible, as can be seen from the case γ=10λ, where the experiment coincides with the theory within the scope of experimental errors. From the above results, we can infer the correctness of the theory and the applicability of the reciprocal theorem. | |||||||
| 書誌レコードID | ||||||||
| 収録物識別子タイプ | NCID | |||||||
| 収録物識別子 | AA00387631 | |||||||
| 資料番号 | ||||||||
| 内容記述タイプ | Other | |||||||
| 内容記述 | 資料番号: SA4146504000 | |||||||
