著者

片岡 克己 安東 潤 中武 一明

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.96, pp.1-8, 1998-09-04

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The hydrofoil catamaran model which is built up with the twin Wigley hulls and the tandem fore and aft set of hydrofoils is used for the numerical calculation and the experiments of this model was performed at Kyushu University. In this paper, combining with a Rankine source method, the SQCM (a simple panel method) is applied to the unsymmetrical flow problem around catamarans. And the running attitude of the model is not fixed in both the calculation and the experiments. Comparing with the experiment we show the interaction between hulls and the hydrofoils for the lift and the wave-making resistance in the high speed range.

著者

川上 寿夫

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.2, pp.140-141, 1950-09

著者

大沼 覚 山本 鷹司 中野 元博 尾上 光賢

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 (ISSN:0389911X)

巻号頁・発行日

vol.38, pp.93-120, 1969

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Qualitative investigation has been carried out on the vibration of superstructure which is assumed to be a shear beam of uniform section on elastic foundation. Coupling effect with vertical vibration of main hull is also studied, and is assessed to be less than 5% on the frequency. Calculation procedure of the vibration, using electronic digital computer, is established treating the deck houses as an array of shear beams connected each other by elastic springs. The qualitative investigation mentioned above is extended in more detail by this procedure. The results show that there exists a relation among the calculated frequencies, which is similar to so-called Dunkerley's formula, i.e. (1.07/Nc)^2=(1/Nr)^2+(1/Ns)^2 where Nc, Nr and Ns are calculated frequencies and Nc; Considering finite values of both vertical-and shearing springs. Ns; Frequency in the limiting case where elasticity of vertical springs tend to infinity. Nr; Frequency in another limiting case where elasticity of shearing springs tend to infinity. Then the lowest frequency is effected predominantly by the lower one of both Nr and Ns. In the actual structures Ns has simple relation with the height of the structure, i.e.: Ns=2600-90H cpm (H: height of superstructure, excepting poop Dk house) On the contrary, Nr undergoes significant changes due to the variety of structure. Vibration experiments have been carried out on 10 ships, and the vibratory behavior of the superstructures is observed. Comparison between measured frequency and calculated value shows that the latter is higher than the former by about 30%. Thus the lowest frequency can be estimated applying the empirical coefficient (0.73) to the calculated values. Estimated frequencies of 10 ships by digital computer agree within±10% of error with their measured values. A brief discussion on the effect of designing factors on the frepuency is investigated by the procedure mentioned above. Finally the simplified method is proposed to calculate natural frequency. Estimated frequencies of 14 ships by this method agree with their measured values within±15% of error.

著者

福田 淳一 小野 雄二

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 (ISSN:0389911X)

巻号頁・発行日

vol.28, pp.53-61, 1964

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The authors tried on to substitute the average sea states by the assumed fully-developed wave spectra following a formula of the Neumann-type: [r(ω,χ)]^2=C_1/ω^6exp(-C_2/ω^2)cos^2χ:0≦ω≦∞ -π/2≦χ≦π/2 The coefficient C_1 and C_2 can be calculated as follows: [numerical formula] H^^〜_<1/3>: average wave height in the average sea states T^^&esim;: average wave period in the average sea states H^^〜_<1/3> and T^^&esim; can be defined respectively as a function of wind velocity based upon the average value of observations. Then, the significant wave height and the average wave period of the assumed wave spectra coincides respectively with the each of the average sea states. A sample of the application of the substitutional wave spectra for the average sea states were presented; The relative vertical bow motions with respect to the water surface of a bulk-carrier in ballast conditions were estimated in the average sea states of North Atlantic, and the critical fore drought with respect to the bow emergence was investigated. The derived results were rather reasonable.

著者

有冨 正男 富 武満

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 (ISSN:0389911X)

巻号頁・発行日

vol.87, pp.185-200, 1994

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Detailed considerations are given for the motion of Foucault's pendulum suspended by a string from a support that can rotate freely. It is well-known that the vertical axis attached to the support of the pendrum rotates with uniform angular velocity due to Coriolis force induced by the rotation of the Earth. In an earlier work, one of the present writers derived an equation of motion for a load suspended from a slewing jib crane attached to a rotating vertical pole. This equation is applied to analyze the motion of Foucault's pendulum. It is shown that the centrifugal force abuot the suport may have a signifficant effect on the pendulum motion. Exact solutions are obtained and experiments on Foucault's pendulum are then conducted to confirm the theoretical predictions.

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.

著者

高橋 雄 有永 真司 石井 哲郎

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.72, pp.213-226, 1986-08-25

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As a high-speed passenger ship, a new concept "Hi-Stable Cabin Craft" is introduced and its technical feasibility was investigated. The "Hi-Stable Cabin" implies highly motion-stabilized cabin, which is mechanically supported by the main ship hull by means of a hydraulic supporting system, with which ship's vertical motion is automatically controlled so as to be suppressed into zero. Therefore, acceleration in the cabin is well minimized so that the passengers will enjoy a trip even in a rough seaway. Computer simulation was carried out regarding the motion control of the Hi-Stable Cabin Craft in waves, and it was confirmed that high degree of stabilization was possible. Model experiment was carried out by use of 3.8 meter-long ship model of the Hi-Stable Cabin Craft equiped with a electroservo mechasism supporting system. Measured pitching motion of the cabin was less than 1/8 of that of the main hull, and remarkable reduction of motion of the cabin was attained. Technical feasibility in practical design of the Hi-Stable Cabin Craft was studied from various aspect such as, general arrangement, hydraulic system, cabin structure, stability, economy of operation, etc. compared with a conventional high-speed craft. As a result, it was considered that the Hi-Stable Cabin Craft appeared to be one of the promissing concept of the advanced marine vehicle for the future.

著者

渡辺 惠弘

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.6, pp.60-67, 1953-07

著者

穂森 繁弘 鎌田 実 佐々木 康夫

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.82, pp.199-208, 1991-09-04

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It has been becoming general that an axial vibration damper is installed on the crankshaft of long-stroke diesel engines in order to minimize the axial excitation forces transferred to the hull through the thrust bearing. But the report that the axial excitation force increased at MCR in spite of the establishment of the damper has been occasionally presented, and besides the fact that peak to peak value (P-P) of the stress fluctuation at crank pin fillet increased in some cases as compared with P-P of the case without the damper has been confirmed as a result of full scale measurement. Therefore, the authors developed the new evaluation system for the vibration and the crank pin fillet stress of the crank shaftings with the axial vibration damper, and introduce the details in this report. In this system, the natural vibration and forced vibration are evaluated by means of a complex eigen value solution. The calculated results of the axial vibration response and crank pin fillet stresses have been compared with the measured ones, and the both show a fairly good agreement respectively.

著者

新開 明二 小西 陽一

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.93, pp.157-166, 1997-03-29

被引用文献数

2

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This paper deals with the application of the Golden Section Number to aesthetic and geometric considerations for the ship design. The Golden Section Number acts an important role in the Dynamic Symmetry, which was proposed by Hanbijji, J. (1920). In order to survey what it's role is in the planning of profile (type) of ship, a series of analysis are executed for some passenger ships in relation to the interior angles of the configuration of ship. Finally, the design procedure are certified on the basis of those analysis.

著者

座間 正人 鳥居 大作 森 俊哲 椛田 剛 伊妻 猛志

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.82, pp.287-294, 1991-09-04

被引用文献数

1

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In order to make clear the corrosion resistance of the STJ (structural transition joint) which affects the reliability required for the STJ applied to the ships with long superstructures, the corrosion tests were conducted for the STJ exposed to marine atmosphere or sea water for max. 53 months, and the following results were obtained. (1) While the parts of aluminum alloy were attacked galvanically by the exposure to sea water for 53 months, the bonding strength of the STJ did not reduce, and the tensile strength and shear strength at bonds of the STJ after the exposure were beyond those of requirements described in the specification of STJ proposed by the Japanese Defense Agency. No stress corrosion cracking was found on the all specimens strained plastically by 0.2% and exposed to sea water for 53 months. (2) While the parts of aluminum alloy were slightly attacked galvanically by the exposure to marine atmosphere for 53 months, the reduction of bonding strength and stress corrosion cracking were not found in any specimens exposed to marine atmosphere. When the STJ is applied to the ships with long superstructures, the STJ is usually coated with paints. It is demonstrate that the bonding strength of the STJ has not been deteriorated even where the paints covered on the STJ are damaged extensively, and the STJ is able to be applied to the ships without any anxiety.

著者

井上 正祐

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.5, pp.78-105, 1953-02

著者

真鍋 大覚

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.33, pp.139-157, 1967-02-28

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台風中心の海洋波生成係数および吹送率を沿岸観測資料を基礎にしてStokes波理論を展開して推定した。眼縁ではとくに岨度が高く,吹送流を大きく,このため船舶は共振が不可能なほど速く流されるとともに,数分以上の長周期波動のため定常風圧傾斜が長く持続する。台風が移動するとき周囲の暴風域に高い波を随伴しているがその分布は物理的には熱伝導と同種の現象であつて,その特性は冬季寒冷前線の波況分布から解析される。

著者

新開 明二 山口 悟 加賀田 拓郎 久保 憲一 口木 裕介 慎 勝進

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.109, pp.93-100, 2005-03-20

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The phenomenon in connection with the economical efficiency and the safety which happen during a voyage strongly depends on the situation of the ship operation process. Although the ship operation process is complicated and it is a random phenomenon, it can be regarded as a stochastic model. Therefore, this paper discusses the stochastic-modeling of the ship operation process. A series of numerical simulation experiment have been executed using the data obtained from voyage record of four tankers. In analyzing the numerical simulation result, the possibility of constructing a forecasting scheme of the ship operation process on the basis of the stochastic-modeling is suggested.

著者

新開 明二 池田 五苗 長尾 健 長 俊寿

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.105, pp.179-186, 2003-03-20

参考文献数

9

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As one of the counterplans to the global warming problem, wind power energy has promising availability in natural energy, and the technical development of wind energy conversion systems is also tackled in Japan. Since the sea has less restriction about social conditions than land, paying attention to the geographical conditions of the Japanese country surrounded by the sea our own time demands, basic investigation about offshore wind energy conversion systems. This paper presents an example of examination for the Miyake island circumference ocean space with emphasis on "wind power investigation", using the prediction program WAsP as wind climate prediction in offshore windmill installations site. The amount of power generation is estimated with regard to some concrete windmills, and then, as one concept in a system design, an energy conversion system (called "offshore wind energy conversion fleet network system") with the windmill of a float type is proposed. It is confirmed that industrialization of offshore wind power is a theme of an energy policy of Japan which deserves examination as a proposal on the other hand.