著者

豊田 昭三 永松 哲郎 ベンカタラマナ カッタ 愛甲 頼和

出版者

社団法人 日本船舶海洋工学会

雑誌

西部造船会々報 89

巻号頁・発行日

pp.33-40, 1995-03-29 (Released:2018-03-01)

参考文献数

5

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An experimental investigation is carried out to study the effects of leading edge fillet and transverse inclination of a strut on a junction flow around and in the wake of the NACA 16-018 aerofoil strut mounted on a flat plate at zero, 5° and 10° angles of attack. The milk injection method is used to visualize the junction flow around and in the wake of the strut on the flat plate at the experiment. The effects of the leading edge fillet and transverse inclination of 30° and 60° of the strut from normal to the flat plate on the junction flow are investigated, furthermore velocity measurements at the leading and trailing edges of the strut normal to the flat plate are carried out to confirm the effect of the leading edge fillet at zero angle of attack.

著者

永松 哲郎 児玉 良明 角川 明 高井 通雄 村上 恭二 石川 暁 上入佐 光 荻原 誠功 吉田 有希 鈴木 敏夫 戸田 保幸 加藤 洋治 池本 晶彦 山谷 周二 芋生 秀作 山下 和春

出版者

公益社団法人日本船舶海洋工学会

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

no.192, pp.15-28, 2002-12

参考文献数

11

被引用文献数

7 12

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This paper is the second half of the report on the study on microbubbles carried out by the SR239 project of the Shipbuilding Research Association of Japan, and describes the full-scale experiment using "SEIUN MARU", a 116m-long training ship that belongs to the Institute for Sea Training. Using numerical analysis and the experimental data obtained in the preparatory study described in the first half of the report, the net energy saving of SEIUN MARU by microbubbles at 14kts was estimated to be 2%. In the full-scale experiment, the trajectory of the generated bubbles was observed using underwater TV cameras and was found to shift more upward than predicted. The local skin friction was measured at several locations on the hull surface, and the skin friction increase as well as decrease by the bubbles was measured. The local void ratio was measured at one point on the hull surface, and the bubbles were found to travel slightly away from the hull surface. The change of the ship speed and shaft horsepower by microbubbles was measured, and the decrease or increase of engine power at constant ship speed was analyzed. In the most cases of the experiment the ship speed decreased by the bubble injection, mainly due to the increase of ship resistance and the decrease of propeller efficiency caused by the bubbles going into the working propeller. But, by carefully choosing the bubble injection location and thus avoiding the bubble entrainment into the propeller, the 3% power saving at a constant speed of 14kts was obtained. By taking into account the power needed to inject bubbles against hydrostatic pressure due to water depth at the injection point, this corresponds to the net power saving of 2%. Thus the net power saving by microbubbles was measured on a full-scale ship for the first time in the world.

著者

永松 哲郎 重廣 律男 堀田 好洋 池田 勉

出版者

鹿児島大学

雑誌

鹿兒島大學水産學部紀要 (ISSN:0453087X)

巻号頁・発行日

vol.52, pp.1-12, 2004-02-27

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The third generation「Nansei-Maru」is a fishery training vessel of the Faculty of Fisheries, Kagoshima University. This ship was built in November, 2002 to carry out the training for navigation and operation of fishing vessel, training of fishery, observation of ocean environment and investigation of marine creatures. The present paper describes about development of the hull form based on the tank tests. The resistance measurement tests, self-propulsion tests and wake measurements at propeller plane were conducted by use of a ship model of 3.5m long in a towing tank. These tests show the designed hull form is entirely satisfactory for her propulsive performance. Next, rolling measurements were made for three kinds of bilge keels both in calm sea and in waves in order to grasp their rolling characteristics. A ship model of 2.0m long was used in the measurements. From the results, the biggest one shows to be the most effective for anti-rolling and then it was selected as the bilge keels of「Nansei-Maru」. Flow visualization tests around ship bow and stern were also carried out by using the 2.0m ship model in a circulating water channel. It is found that there is no problem for entrainment of air bubbles into the sonar dome and severe turbulence at stern. Finally, sea trial tests by the full scale ship were conducted and it is confirmed that ship speed, turning performance and so on are satisfied for their requirements.