著者

春海 一佳 Kazuyoshi HARUMI

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.28, no.6, pp.p321-341, 1991-11

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The validity of six k-ε models was investigated by comparing the results of each model for the fully developed turbulent channel flow to the results of the direct numerical simulation(DNS) by Kim, Moin and Moser (1987). Most models show good agreement with DNS for the mean velocity profile, while they have disagreements for the profile of the turbulence energy k. The near-wall behavior of the viscous diffusion term and dissipation term in every model except Kasagi's model have a qualitative discrepancy from the DNS results. The failure in the prediction of the k profile may be due to this fact. The pressure-turbulence diffusion terms in k and ε equations are inconsistent with the near-wall behavior which are derived theoretically. A new model is presented which modifies the pressure-turbulence duffusion term and these defects are reduced to more closely satisfy the theoretical behavior. These modifications revise the behavior of the viscous diffusion term and dissipation term to give better agreement with the DNS results. In addition, these modifications effect the heat transfer calculation, especially for high Prandtl number fluids.

著者

染谷,実

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告

巻号頁・発行日

vol.27, no.5, 1990-11-30

著者

松倉 洋史 三友 信夫 松岡 猛 運輸省船舶技術研究所システム技術部 運輸省船舶技術研究所システム技術部 運輸省船舶技術研究所システム技術部

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.37, no.1, 2000

著者

高橋,肇

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告

巻号頁・発行日

vol.7, no.7, 1971-02-28

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It is very important to measure the wake distribution accurately from the point of view of the propulsive performance including the problems of cavitation and vibratory forces induced by the propellers. At the 11th and 12th International Towing Tank Conference, the characteristics of five-hole pitot tubes and the measuring technique of the wake behind the ship model always come up for discussion. Recently, pitot tubes of the N.P.L. type have been calibrated in the Ship Research Institute. The report deals with the discussion of the characteristics of two 5-hole pitot tubes, and then the comparison between the wake distributions measured behind the model using the pitot comb of the Prandtl's type and the 5-hole pitot tube, are presented. Finally the effect of the two types of wake distributions upon the calculated bearing forces and moments are shown.

著者

成合 英樹 運輸省船舶技術研究所原子力船部

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.16, no.4, 1979

著者

鳥野 慶一 吹上 紀夫 折戸 義晴 山越 康行 後町 光夫 加賀 壽

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.33, no.2, 1996

著者

三友 信夫 松倉 洋史 松岡 猛 Nobuo MITOMO Hiroshi MATSUKURA Takeshi MATSUOKA 運輸省船舶技術研究所システム技術部 運輸省船舶技術研究所システム技術部 運輸省船舶技術研究所システム技術部

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.37, no.3, pp.77-141, 2000

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For large and complex systems, full and enough investigation is required not to damage the public or operators, before design, construction and operation. Especially chemical plant, nuclear power plant and ships etc. must not cause any large accidents because of the safety of the public or lots of people working there. So, the new assessment, PSA (Probabilistic Safety Assessment), becomes popular in addition to deterministic safety assessment for these complex systems. In this paper, as an example of an application of PSA for the marine field, the event tree analysis method was applied to the Titanic accident. Factors which related to the Titanic accident were all selected under the those day's surrounding condition. The occurrence probabilities of the factors have been estimated from various data. The probability that the Titanic encounters the sever accidents, and number of fatality have been calculated. This report has shown the detailed procedure of event tree analysis for a marine accident. It has also shown the effectiveness of event tree analysis for the analysis of accident causes and for the improvement of the safety for various large complex systems.

著者

二村 正 石田 茂資 渡辺 巌 Tadashi NIMURA Shigesuke ISHIDA Iwao WATANABE 船舶技術研究所運動性能部 船舶技術研究所運動性能部 船舶技術研究所運動性能部

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.32, no.5, pp.233-264, 1996-02

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Capsizing and re-righting performance of three types of sailing yachts, IOR racer type, conventional type and intermediate type, was experimentally investigated in beam transient waves with various wave heights. The effect of CG height, existence of mast and flooded water volume on the critical wave height for capsizing and for re-righting was examined. It was characteristic in the capsizing motion of the models with mast that the rolling motion almost stopped just after the mast plunged into the water because of the hydrodynamic impulsive force on the mast. The stopping heel angle was almost independent of hull forms and model conditions. As a result the static stability vanishing angle, θv, was crucial for capsizing even in flooded conditions. As for re-righting motion θv was also crucial. It was clarified that the IOR racer type yacht is easier to capsize and harder to re-right because of its small θv value even if it has large GM. The way of improving the capsizing resistance was discussed. Lowering the center of gravity or attaching a small float on top of the mast could be an easy and effective way to prevent capsizing disaster because that leads to a large θv value. The flooded water, in general, enlarged θv, that made the models capsize-resistant. But for re-righting motion the relation between the critical wave height for re-righting and θv was complicated, because the water prevents the motion of the models at the same time. The probability of capsizing and re-righting in a sea state with ISSC spectrum was examined. Moreover the capsizing duration time was calculated as a safety index. It was reconfirmed again by the probabilistic approach that θv is very important for the safety of sailing yachts. θv of 120 degrees was proposed as an safety criteria.

著者

中田,正也

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告

巻号頁・発行日

vol.8, no.7, 1972-02-28

著者

山越 寿夫 片岡 巌 山越 寿夫 竹内 清 金井 康二 伊藤 泰義 植木 紘太郎 野間口 道義 綾 威雄 船舶技術研究所 船舶技術研究所 船舶技術研究所 船舶技術研究所 船舶技術研究所 船舶技術研究所 船舶技術研究所 船舶技術研究所 船舶技術研究所

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.8, no.7, pp.207-208, 1971-12

著者

成合,英樹

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告

巻号頁・発行日

vol.15, no.2, 1976-03-20

著者

勝又 健一

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.30, no.5, 1993

著者

伊藤 泰義 井上 圭典

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.34, no.3, pp.99-140, 1997

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This paper is divided into two parts. Hie first part outline of GPS,while the second part describes the method of fixing the position ,which can minimize the effect of SA, and gives the result of an experiment that attests to the efficacy and advantage of the method. Starting with introductory remarks the first part deals with the following themes : the principle of position fix, code pseudoranges, phase pseudoranges, the kinematic method, the OTF technique, and lastly DGPS network both in Japan and the rest of the world. The second part addresses itself to the following contents: the calculating method of satellite coordinates and its examples, the relationship between the age of ephemeris and the degrees of precision of satellite coordinates, the construction of the observation equation and its solution, the relationship between the stability of the solution and the determinant of the coefficient matrix, examples of inferior precision caused by the effect of SA, and examples in which errors caused by SA are reduced. Whereas the effect of SA normally produces random variation for a fixed position with the error ranging from 50 to 150 meters, our method could reduce the amount of variation of the error by 50 % approximately. A glossary of GPS terminology is appended at the end of the paper.

著者

山路 昭雄

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.37, no.6, 2000

著者

渡辺 健次 森下 輝夫 内藤 正一 菅 進

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.20, no.2, pp.93-128, 1983

被引用文献数

2

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This project is for hydrogen production with solar energy on a huge raft floating on the South Pacific Ocean and for transport of liquified hydrogen. In previous papers, authors proposed a new raft system and showed that the system is efficient for collecting solar energy and able to follow solar motion in the range of allowable error. In this paper, the feasibility on the total plan is studied from technical view point and other ploblems are investigated ; the polution and efficiency reduction of reflecting mirrors by sea-salt particles, transport of liquified hydrogen by tankers and meteorogical and ecological influence by the existence of huge raft floating on ocean are discussed. Energy conversion ratio is about 20 per cent and total liquified hydrogen income of the system is about 5,000 ton per year. Consequently the project is feasible from technical view point.

著者

浜島 金司 渡辺 健次

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.19, no.4, pp.285-303, 1982

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In this paper, optical problems of sun following on the sea is discussed. Main difficulty is that angular velocity of the raft is very large when the sun passes near the zenith. This difficulty is released by mean of adequate rotation of raft that reduces the angular velocity and minimizes the loss of incident solar energy resulting from sun following error.Furthermore, some formulae for sun following that is necessary to use in the third and the fourth reports are showed, for example, raft angular velocity, acceleration, moment, power, and energy for raft rotation etc.

著者

遠藤 久芳 菅 信 大松 重雄 山川 賢次 菅 進 渡辺 健次

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.19, no.4, pp.257-283, 1982

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The study had been started from the review^<19)> of "Plan of Ocean Raft System for Hydrogen Economy"^<1)> which was proposed by Ohta^<1)> and Veziroglu in 1977. The project was for hydrogen production with solar energy on a huge raft floating on the South Pacific Ocean and for transport of liquefied hydrogen.Since their raft system was found to have some fatal defects in hydrodynamical and structural characteristics, an alternative plan of new raft system was proposed in which those defects are improved.In these papers (three reports will continue after this), authors carried out the feasibility study on the total plan only from technical view point. Economical view point was excluded here.In the first report, a new raft system is proposed as an alternative one. After natural condition such as wave, current and wind of the concerned area (8°S, 138°W) was surveyed, environmental force was estimated and the behavior of the raft was investigated both analytically and experimentally. Detail design of each structural members was conducted under consideration of the structural response for the load mentioned.The new raft system proved to be efficient for collecting solar energy and to be superior in hydrodynamical and structural characteristics.

著者

花岡 達郎 Tatsuro Hanaoka 運輸省船舶技術研究所運動性能部

出版者

運輸省船舶技術研究所

雑誌

船舶技術研究所報告 (ISSN:0495775X)

巻号頁・発行日

vol.5, no.6, pp.217-257, 1969-01

被引用文献数

3

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The purpose of the present paper is to give a fundamental theory of hydrodynamics concerning a screw propeller on the status of both potential and vortex theory.Chapter 1 is a brief description regarding historical aspect of the recent development in propeller theory.Chapter2 is devoted to the theory of a wing with finite span. We have been made familiar with propeller theory through wing theory. The description will be useful for us to understand the remainder of this paper.In this paper the propeller theory consists of three parts. The first deals with the fundamentals of the theory in the frame of linearized theory in Chapter 3.In Chapter 4 and 5, the theory previously discussed is developed to nonlinear theory and theory of wake-adapted propellers.