著者

出淵 巽 藤嶋 範平 荒木 勤 出淵 巽 山本 武藏 菅 四郎 湊 一磨 平賀 譲

出版者

公益社団法人日本船舶海洋工学会

雑誌

造船協會會報 (ISSN:05148499)

巻号頁・発行日

no.55, pp.57-100, 1935-03-25

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The effect of fouling upon the resistance of ships was examined by the towing experiments with the ex-destroyer Yudachi at various stages of fouled surface after 4,75,140,225 and 375 days out of dock ; the speeds experimented with were up to 20 knots at each fouled condition. After these experiments the author studied the effect of fouling on the propulsive efficiency applying the above-mentioned results of towing experiments to the trial results of a first-class destroyer. The chief conclusions drawn from these investigations are : (1) Frictional resistance of ships having fouled bottoms can be expressed by the following formula : -R_f=f S V^<2-1>, where R_f=frictional resistance in kg., S=wetted surface area in m^2., V=speed of ship in knots, f=coefficient of frictional resistance which varies with the weight of fouled substances per unit area as shown in Fig.6. (2) Propulsive efficiency is affected scarcely by the bottom fouling.