WEKO3
アイテム
Hobutumen no Onkyogakutekino Seisitu ni tuite. (Sono 2)
https://jaxa.repo.nii.ac.jp/records/35467
https://jaxa.repo.nii.ac.jp/records/35467f671ceb8-5d08-494d-8199-1632332c6ecd
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
SA4147325.pdf (535.7 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 | Hobutumen no Onkyogakutekino Seisitu ni tuite. (Sono 2) | |||||||||
| 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 Parabolic Reflectors. (Part II.) | |||||||||
| 著者 |
SATO, Kozi
× SATO, Kozi
× SASAO, Masaaki
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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 7, 号 93, p. 339-356, 発行日 1933-02 |
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| 抄録（英） | ||||||||||
| 内容記述タイプ | Other | |||||||||
| 内容記述 | Several years age, one of the authors measured the intensity of sound received through a conical horn with its axis set at different angles θ to the ray of sound. The most remarkable of the results is that the distribution of intensity as function of the angle θ mainly depends upon the wave-length of the sound, and only slightly upon the geometrical shape of the conical horn if the diameter of the opening be the same. It is a matter of interest to investigate whether a parabolic reflector has also such a property. In the preceding paper on parabolic reflector, its sound field has been investigated in detail as function of wave-length. As a continuation of it, the present paper deals with the directive properties of parabolic reflector. The procedure of the experiment is similar to that of the preceding one. The shapes of the parabolic mirrors used in the experiment are of three different varieties shown in Fig.1 (on the page 342). Each has the same opening of 40cm. diameter and is made of aluminium 2cm. thick. It is made to rotate horizontally round the centre of its opening and as the receiver of sound, a small conical horn of 3cm. diameter is placed at the focus in rigid connection with the parabolic reflector. (See Fig 2 on the page 343). The sound concentrated at the focus is received through the small cone and conducted through a long rubber tube to the Rayleigh disc by means of which its intensity is measured. The distance between the source and the opening of the parabolic reflector is about 600cm. which is large compared with the diameter of the opening, so that on the opening, the incident wave can be treated practically as plane one. The experiment was performed in a carefully designed sound-proof chamber. The results of the experiment are shown in Fig.3 (on the page 344) and Fig.4 (on the pages 346-348). In the figures, the intensity of sound received is shown in polar diagrams as function of the angle (θ) between the axis of the parabolic reflector and the ray of sound. Fig.3 shows the directive properties of the parabolic reflector (II) for different pitches of sound c^1, c^2, c^3 and c^4. For c^1, the intensity of sound received is nearly equal for all values of θ. On the contrary, for c^4, it is considerable only for small values of θ. The directive property increases as the wave-length decreases. Fig.4 shows the directive properties of the parabolic reflectors I, II, III for c^1, c^2, c^3 and c^4. It can easily be seen from these figures that although the parabolic reflectors are quite different in shape, the corresponding curves for any given pitch of sound are similar to one another. Hence we can conclude that the directive property of the parabolic reflector depends only slightly upon its geometrical shape if the diameter of the opening be the same. Lastly, the reflector (I) has been compared with respect to the directive property with the conical horn of the same opening and depth. For all the pitches used, no marked difference has been found between them. (See Fig. 5 on the pages 349-351). The above experiment is referred to the property of the parabolic reflector as a receiver of sound, but by the reciprocal relation, the directive property of a receiver will be the same as that of a radiater. If the depth and opening are given, the magnifying power of a parabolic mirror is much smaller in general than that of a conical horn and as for the directive property, there exists no appreciable difference between them. Therefore, as a collector or radiator of sound, the former is far inferior to the latter. | |||||||||
| 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: SA4147325000 | |||||||||
