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設計図面から各種2艘曳並びにトロール網の抵抗および網口高さを求める近似式について
https://fra.repo.nii.ac.jp/records/2011474
https://fra.repo.nii.ac.jp/records/201147467aa22ef-4697-4a1c-8b0b-6af6e9353e33
| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2024-10-11 | |||||
| タイトル | ||||||
| タイトル | 設計図面から各種2艘曳並びにトロール網の抵抗および網口高さを求める近似式について | |||||
| 言語 | ja | |||||
| タイトル | ||||||
| タイトル | On the hydrodynamic resistance and the gape height of pair and otter trawl nets estimated by approximate equations | |||||
| 言語 | en | |||||
| 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 | |||||
| アクセス権 | ||||||
| アクセス権 | open access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_abf2 | |||||
| 著者 |
谷口, 武夫
× 谷口, 武夫 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Usually the hydrodynamic resistance and the gape-height at net mouth of a trawl net are empirically determined on the basis of either model or field experiments. However, it would be certainly helpful for a net-designer, if a formula is made available for estimating the resistance or the gape-height of various trawl nets from a construction plan of the net. By simplifying TAUTI's theory on the plane net in motion through the water, the hydrodynamic resistance, Rn (kg), of a trawl net may be expressed as Rn= k(D/L)m S*p V2-m. (2) And, with the similar consideration to the avove, the gape-height, Hn (m), of a trawl net is indicated as Hn=h (D/L) m H* V". .. (3) In both avove equations, k and h are the coefficient of proportion, p the density of sea-water (105 kg sec2/m4) and V the towing speed (m/s). (D/L) signifies the average ratio of the diameter of net twine to the length of each mesh-bar, which is computed by g(D/L) :· A; ΣΑΙ (D/L)m= (i =1, 2, 3, ...... n) ...... (4) in which (D/L), and A, show (D/L) of i-th panel of the net and its stretched area (m2), respctively. And, S* and H* indicate the projected area (m2) of the net on the direction of motion and its height (m) in the ideal condition, which are approximately given by the following each equation S* = sin [2L, H*+Lw(Bu+H*)| .(5) and H* = 1/2(Bs+2Bws-2L, sin ), .(6) here ß is the angle between the wing and the direction of motion, L and B with suffic sign the length and the breadth of the parts of the net arranged on a construction plan (Fig. 1). From model and field experiments of various pair and otter trawl nets and gear showen in Tables 1 and 2 or in Fig. 2-a and -b, the relation between the resistance, Rn, and the towing speed, V, is as in Fig. 3 and can be approximately expressed as R2 co V1.5, viz. m = -0.5, irrespective of type or size. And coefficient of proportion, k, vary with types and is computed as about 3.7 for both a fish and a shrimp nets in pair trawl but as 1.3 for a combined use net, and as about 2.7 for each seam type otter trawl with the exception of 1.9 for two-seam type net (Table 3). The other hand, the relation between the gape-height, Hn, and the towing speed, V, is as in Fig. 4 and can be approximately expressed as Hn o V-0.8, and the coefficient of proportion, h, is about 11.0 for all new type nets in pair trawl but as 5.6 for a old type fish net, and about 16.7 for a usual otter trawl net consisted of four or six seam except for 7.6 of a specific two-seam type net (Table 4). | |||||
| 言語 | en | |||||
| 書誌情報 |
ja : 水産大学校研究報告 en : The Journal of the Shimonoseki University of Fisheries 巻 32, 号 1/2, p. 1-14, ページ数 14, 発行日 1984-01 |
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| 出版者 | ||||||
| 出版者 | 水産大学校 | |||||
| 言語 | ja | |||||
| 出版者 | ||||||
| 出版者 | the Shimonoseki University of Fisheries | |||||
| 言語 | en | |||||
| ISSN | ||||||
| 収録物識別子タイプ | PISSN | |||||
| 収録物識別子 | 0370-9361 | |||||
| 書誌レコードID | ||||||
| 収録物識別子タイプ | NCID | |||||
| 収録物識別子 | AN00124678 | |||||
| 情報源 | ||||||
| 識別子タイプ | Local | |||||
| 関連識別子 | fishu_k_32_1 | |||||
| 関連サイト | ||||||
| 識別子タイプ | URI | |||||
| 関連識別子 | https://agriknowledge.affrc.go.jp/RN/2010292951 | |||||
| 言語 | ja | |||||
| 関連名称 | 日本農学文献記事索引(agriknowledge) | |||||
