著者

Ueno Keizo NAGAMATSU Tetsuro

出版者

公益社団法人日本船舶海洋工学会

雑誌

西部造船会会報 (ISSN:0389911X)

巻号頁・発行日

no.41, pp.1-18, 1971-03-31

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There have been many investigations into the effect of restricted water on wave-making resistance. In numerical calculation of the wave-making resistance, however, ship forms were represented by source distributions obtained for the unbounded water instead of those for the restricted water. In the present study the authors consider the effect of restricted water to obtain source distributions and calculate the wave-making resistance to compare with the results derived from the source distributions in unbounded water. Numerical calculations are carried out on a ship in a canal with rectangular cross section. The ship is represented by stepped distribution of sources and sinks on the centre plane. The side walls aud the bottom of the canal are replaced by infinite series of image sources and sinks. Calculations are made on the following ship form and canal sizes. Ship form Parabolic water line and frame line L/B=L/T=10 Canal size W/L=0.25, 0.5, 0.75, 1.0, 1.5, 2.0 H/L=0.25, 0.5, 0.75, 1.0 where L=ship length, B=ship breadth, T=draft, W=canal width, H=canal depth From the results of the calculations, the following conclusions are derived. (1) The source density representing the same ship form increases with the presence of canal walls and decreases with the presence of canal bottom. (2) For practical purposes, the wave-making resistance in restricted water may be calculated by using the source distribution obtained in unbounded water. (3) When the canal is wider than 3/2・L and is deeper than 3/4・L, the efect of restricted water may be neglected in practical application.