網地剛体模型近傍の流速分布 / "/"今井, 健彦(1000020041709)/""今井, 健彦 ,  "/石崎, 宗周(1000090244269)/"石崎, 宗周 ,  "/不破, 茂/"不破, 茂 ,  "/久津輪, 修一/"久津輪, 修一 ,  "/金, 碩鍾/"金, 碩鍾 ,  "/洪, 性完"/"洪, 性完"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 43 ( 1 )  , pp.1 - 9 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"This paper deals with flow-profiles around an enl...

"This paper deals with flow-profiles around an enlarged solid model of netting which was set into an experimental flume tank on every half angle of Θ, (range from 0 to 3Θ of setting angles), to clarify flow distribution around the model. In this case Θ means the angle of attack when mesh-hall faded out from the projective plane. A thin film flow-meter with corn shaped probe was used in the experiment. Measurements were carried out on 110 fixed points, 24 points around mesh, and 5 points inside mesh-halls at every attack angles on a horizontal plane. The flow-speed was maintained at 10 cm/s, and Reynolds number at 1.9×10^3. From the resultant profiles, the fluid-dynamical force acting on each leg was similar with the case larger than 3Θ of attack angles."

円錐網の抗力係数とレイノルズ数 / "/"洪, 性完/""洪, 性完 ,  "/今井, 健彦"(1000020041709)/"今井, 健彦"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 45 , pp.29 - 35 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"A fluid dynamic of midwater trawl and codend are ...

"A fluid dynamic of midwater trawl and codend are associated with a flow velocity inside the net. This study investigates the relationship between drag coefficient of conical nets and Reynolds number which concerns with a flow velocity inside the net. In order to measure the drag of conical nets, twenty models of different open area ratios, which composed five kinds of twisted knotless nettings and four kinds of hanging angles, were tested in the flume tank of Kagoshima University. The mouth of each net was attached to a circular shaped frame to maintain geometric feature, and the nets were set into the flume tank normal to the flow direction. The velocity was monitored by a supersonic digital current meter which is installed in the flume tank, and the drag was measured using a three-component load cell. Measured values were stored in a data file of a computer for analysis. If uniform hanging angle is the significant factor affecting the drag of the conical nets depended on the open area ratio. When the representative velocity U_m/ β and representative length d were used as a characteristic velocity inside the net. And scale, a more general correlation between the drag coefficient and the Reynolds number are found using the exponential linear regression. C_D' was found to be C_D'= 18.88 Re'^<-0.63>."

円錐網の周りの流速分布 / "/"洪, 性完/""洪, 性完 ,  "/今井, 健彦"(1000020041709)/"今井, 健彦"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 45 , pp.21 - 28 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"This paper deals with the velocity around the con...

"This paper deals with the velocity around the conical net in the flume tank at the Faculty of Fisheries, Kagoshima University. Eight types of conical nets were used for the experiment ; out of which four kinds were the same netting with different hanging angles, and the other four were the same hanging ratio with different nettings. The mouth of each net was attached to a circular shaped frame of the same dimension, and the test speed was 80 cm/s at a steady flow. The flow velocity in the test sections were measured with a hot film flow meter. The following results were obtained : 1) The velocity around the nets can be classified into 3 fields, inside net, in the boundary layer in which the flow is passed through a mesh hall and outside net. As the open area ratio (β) became smaller, the velocity of inside net increased but the velocity of boundary layer decreased. 2) The shape of conical net in a flow field depended on the mesh number rather than to the open area ratio of mesh. 3) The theoretical analysis was carried out on the continuity equation to derive an empirical equation for the average flow velocity on the cone type nets."

オッターボードの研究 : 多翼型オッターボードの性能について / "/"今井, 健彦(1000020041709)/""今井, 健彦 ,  "/小山, 重美"/"小山, 重美"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 24 , pp.87 - 97 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"Studies on midwater otter boards which are mainly...

"Studies on midwater otter boards which are mainly composed of Wing board (Larsson’s Phantom trawl), Dualfin board (British Columbian trawl), Hydrofoil otter board (Süberkrüb) and Bie-plane otter board (Kobayashi), are comparatively recent development. This paper deals with the performance of multi-plane otter board, whose structure is similar to that of a paravane-shearing-board. The model experiments were carried out on sea and at circular tank. The model was made with galvanized iron-plate (0.48 mm in thickness), dimension of the model being 23.4 cm in length, 21.7 cm in width, and 225 g in weight, respectively. The results obtained are as follows; 1．The critical attack angle of the multi-plane otter board was determined to be 25.5 degrees. 2．Through the results of fig. 6 the relationship between lift-force and towing-speed, and, between drag-force and towing speed may be expressed in the following empirical formulas. L=42.7V^{1.99}. D=34.4V^{2.05}. 3. The ratio of lift and drag in the multi-plane otter board was ascertained to be 1.28, which shows the intermediate value between the upright type otter board (C_L/C_D=1.85), and the ordinary one (C_L/C_D=0.8)."

夏季東支那海南部のホンサバについての知見(予報) / "/今井, 健彦(1000020041709)/"今井, 健彦

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 16 , pp.76 - 84 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

Some investigations on the habitat of the common j...

Some investigations on the habitat of the common japanese mackerel were carried out by the "Kagoshima Maru", training ship of the Faculty of Fisheries, Kagoshima University, in the southernwaters of the East China Sea in summer, both in 1964 and in 1965. The results are obtained asfollows:1) It was in the sea-front situated at the cross-section, lat. 29°-30' N and long. 124°-00' Eand its vicinity that the confirmed catch of the common japanese mackerels including that of otherfishes was carried out with the trawl-net in June and August, 1964.2) The fork length of the common japanese mackerel caught there, was ranged in 280~350mm.3) It was ascertained that, in the littoral water mass, water temperature 17~22°C and salinity34.0~34.5‰ in summer, the habitats of some schools of the common japanese mackerels were tobe found at the water near the bottom.
1. 夏季に東支那海南部海域に棲息しているホンサバとその漁場環境について調査した。2. 北緯29°-30',東経124°周辺の水深70mの海域で6月と8月にトロール網で漁獲された魚類の中にホンサバが混獲された。3. ホンサバの体長範囲は280~350mmであった。4. ホンサバは夏季大陸沿岸性の水塊中で水温17~22°C,塩分34.0~34.5‰の範囲の底層近くに棲息しているものと推定される。

かご漁具の形状と漁獲機構 / "/"不破, 茂/""不破, 茂 ,  "/川野, 和昭/"川野, 和昭 ,  "/杉本, 裕司/"杉本, 裕司 ,  "/石崎, 宗周(1000090244269)/"石崎, 宗周 ,  "/今井, 健彦"(1000020041709)/"今井, 健彦"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 46 , pp.21 - 30 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"Various shapes of entrance in basket traps were u...

"Various shapes of entrance in basket traps were used in rivers of southern Kyushu and their fishing mechanisms were studied. Dimensions of basket traps were measured and their physical characteristics were examined. The external shapes of entrance were divided into two categories by current conditions at the area where basket traps were used. The basket traps in deep rivers have a square shape with a short, large angled throat. Two types of basket traps were used in shallow rivers ; one has a cylinder shape with a long, small angle throat, and the other has no throat. The angle of entrance without throat was inclined. The curved shape of entrance seemed to guide fishes into the basket trap and to hold them inside. The inclined angle of entrance for shrimp was smaller than that for fish. It may be assumed that the shapes and angles of entrance in basket traps could be affected by current conditions in and around the traps as well as by swimming behaviours of the target fish."

鹿児島市沖合に設置された人工魚礁 / "/"不破, 茂/""不破, 茂 ,  "/今井, 健彦(1000020041709)/"今井, 健彦 ,  "/田畑, 静夫/"田畑, 静夫 ,  "/金, 碩鍾/"金, 碩鍾 ,  "/久津輪, 修一/"久津輪, 修一 ,  "/熊澤, 泰生"/"熊澤, 泰生"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 40 , pp.111 - 121 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"The fish gathering effect and setting condition o...

"The fish gathering effect and setting condition of the artificial reefs were studied on the basis of field experiments off Kagoshima City. Three types of artificial reefs: one concrete block reef, two bus reefs and one lava reef were surveyed by scuba diving. Field results were analyzed with respect to the fish fauna and dispersion of reef after setting on the sea bottom. The results are as follows. Bus reef showed the highest fish gathering effect. However, poor fish fauna was found at the reefs north of west Sakurashima pass as compared to the others. The distribution of the reefs differed from the scheduled arrangment. The difference seemed to be caused by the errors at setting due to movement of marker buoy and inaccuracy of positioning of the ship. These suggest that setting operation should also be considered in order to increase the accurarcy of reef arrangment."

鹿児島大学学内共同利用回流水槽の設計思想と特徴およびその性能 / "/"米盛, 亨(1000080041698)/""米盛, 亨 ,  "/奈良迫, 嘉一/"奈良迫, 嘉一 ,  "/前川, 博/"前川, 博 ,  "/今井, 健彦(1000020041709)/"今井, 健彦 ,  "/中山, 博/"中山, 博 ,  "/豊広, 利信"/"豊広, 利信"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 36 ( 1 )  , pp.67 - 87 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"This report represents a general description of t...

"This report represents a general description of the new circulating water channel which wassituated in the site of Faculty of Fisheries, Kagoshima University in March 1986.To arrange the basic design for the water channel, a committee was organized and theprincipal items were determined.According to the specification, water capacity in the system : 80 tons, size of the measuringsection : 6.0 m in length, 2.0 m in width, 1.0 m in depth, maximum water velocity at themeasuring section : 2.0 m/s.Moreover, demands were presented in connection with the capability of velocity profile,turbulent intensity, stationary waves and water surface gradient.The results of the running examinations were almost satisfactory except on velocity profile.Among the difficulties concerning velocity profile, the setting of revolution for twoaccelerators is considered a subject in a future study."

空中垂下法によるグランドロープ形状の検討 / "/"不破, 茂/""不破, 茂 ,  "/桜井, 広光/"桜井, 広光 ,  "/今井, 健彦(1000020041709)/"今井, 健彦 ,  "/石崎, 宗周(1000090244269)/"石崎, 宗周 ,  "/金, 碩鍾/"金, 碩鍾 ,  "/洪, 性完"/"洪, 性完"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 43 ( 1 )  , pp.11 - 20 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"This study deals with the shape of groundrope und...

"This study deals with the shape of groundrope under the towing condition of bottom trawl net. The shape of groundrope depends on an equilibrium of three forces: fluid-dynamic resistance of netting, fluid-dynamic resistance of the groundrope and sliding frictional force against the sea bottom. It was assumed that the groundrope consisted of a connection of segments. The vertical, horizontal and tangential components were considered to be in equilibrium acting on the segment. The horizontal component acting on each segment of the groundrope was constant at any part. The spread of wing's end was fixed beforehand. The vertical component, acting on each segment of the groundrope, was calculated based on the relative ratio of netting area which was connected to each part of groundrope of the whole netting area. The shape of groundrope was analyzed based on the distribution of vertical components of segment. The model experiments were carried out using the method of mechanical simulation; and the model net was suspended on the vertical meshed board. The fluid-dynamical resistance of the net was simulated by equivalent weight secured at the end of lacing lines. The frictional forces was simulated by attaching equivalent to of the groundrope of the model net in water. And the shape of netting was simulated by rubber ballons fixed inside the trawl net. The shape of groundrope was expressed by the two dimensional coordinates using the grid of board with 2 cm scale. A close agreement was obtained between the analytical and mechanical simulated values in the shape of groundrope."

ごち網に関する研究 I : 網の動態について / "/"肥後, 伸夫(1000010041691)/""肥後, 伸夫 ,  "/不破, 茂/"不破, 茂 ,  "/今井, 健彦"(1000020041709)/"今井, 健彦"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 26 , pp.137 - 145 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

The fishing method of the Gochi Net fishery consis...

The fishing method of the Gochi Net fishery consists in scooping up the fish school groupingabove a reef.The amount of the fish caught by this net depends upon the following items ：ι the distance between the point at which the net becomes detached from the seabottom andthe point where a reef is situated. h the height of the net which is being passed above the reef.The moving pattern of the net was analyzed theoritically into the following equation ： ･･･[the rest omitted]
"ごち網の漁法は網を着底させた後,斜上方に掬い上げて魚礁上の魚群を漁獲する形式のものである。網の漁獲量を左右するものは,網の離底点と魚礁間の距離(ι)と魚礁上の網の通過点の高さ(h)である。そこでごち網の動態を表わすιの値を理論的に求めると次式で表わされる。(式 省略)ここでh'は魚礁の高さ(m),Tは船尾における曳綱の張力(kg),wは曳綱の水中重量(kg/m),Dは水深(m)である。w,D,h'は既知量,Tは操業結果から求められる値,hは音響測深儀の記録から求められる値である。Fig.4の網と曳綱を用い水深28mの漁場で操業した場合のιの値を求めると9.4mとなる。次ぎに模型実験によって,網の着底から網が魚礁上を通過する迄の網成りを検討した。その結果,網の移動速度が速い程,離底は遅く,離底直後の網口高さは低く,網口巾は早く狭くなることが判った。潜水観察の結果,網の移動距離は模型実験値と略一致し,また網口巾が離底直前に多少拡がる現象を認めた。"