著者

平川 嘉昭 平山 次清 高山 武彦

出版者

社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.11, pp.61-71, 2010 (Released:2011-01-28)

参考文献数

5

著者

黒田 貴子 原 正一 松田 秋彦

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.6, pp.339-345, 2007 (Released:2008-03-18)

参考文献数

8

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In order to make a plan of ship towing, it is necessary to investigate the towing performance of the tow ship, status of the towed ship, external force acting on the towed ship and sea conditions. The factors of the towing performance are derived from the towing gear and main engine power, which are evaluated by the bollard pull test in the case of the tugboat. When the general ship instead of the tugboat makes a towing operation, the towing performance with the main engine power is crucial. It is important to know the towing performance of the tow ship and tow force depending on the size of towed ships in several sea states in the emergency towing by the general ship.The bollard pull test and towing test in calm and rough seas have been carried out to investigate the tow force and tow power, critical tow force and the condition of safe towing. The towing safety factor is defined by the critical tow force divided by the maximum towline tension during towing. The factor less than 1 indicates the disability of towing. The critical condition is shown by the value between 1 and 2. Lastly its value larger than 2 indicates the safe towing. The towline tension is calculated by the Optimum Towing Support System developed by the National Maritime Research Institute. In this calculation, the patrol vessel as tow ship tows 5kinds of ships in several sea states. By using the ratio of critical tow force and calculated towline tension, the towing safety factor is estimated and the chart for the critical towing performance in several sea states using the displacement ratio between tow and towed ship has been shown. Even the operator of the general ship will be able to know the possibility of the safe emergency towing using the displacement of the towed ship in certain weather condition in this chart.

著者

桃木 勉 長野 真二郎 池田 良穂

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.9, pp.257-264, 2009 (Released:2009-10-08)

参考文献数

5

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Recently, fast car ferries of catamaran type have become larger and larger. In beam waves, motion of catamaran is relatively severe because of its large stability. Therefore, in beam waves, tilt or turn over of cars is concerned for such catamarans. If relationship between wave height and tilt of cars is clarified, safety voyage without lashing will be able to judge before sailing from port.A method of judgment of tilt of cars on deck was proposed by Kuwano. In this method, however, only rolling motion is taken into account. It is necessary to take other motions into account for higher precision of the judgment of tilt of cars on deck. A new method considering heave, sway and pitch as well as roll motion is developed in the present paper. Model experiments to check out the relevance of the new method and the effect of motions except rolling on behavior of vehicles on decks are carried out.The method is applied to a 112m wave piercing catamaran, and criteria of wave height for tilt of vehicles on decks are predicted.The predicted results demonstrate the effects of other motions except rolling are significant in some cases. It is confirmed that the most critical wave period of tilt of vehicles on decks of the wave piercing catamaran is about 6.0 to 8.0 seconds.

著者

今北 明彦 安田 章宏

出版者

社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.6, pp.379-386, 2007 (Released:2008-03-18)

参考文献数

10

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This paper describes numerical simulations and experimental results of dynamic response of a cylindrical floating structure subjected to an underwater explosion. An explosion was generated by wire explosion method under the center of bottom plate. Responses of the cylinder were recorded in the experiments with three different offset conditions. Nonlinear explicit finite element method and finite volume method were used for the structural analysis and the fluid analysis respectively. Compressibility of fluid and fluid structure interaction were taken into account in the numerical simulation. Explosion bubble shape was observed with a high speed camera and were compared with the numerical simulation results. Experimental results of time histories of bottom surface pressures and displacement of the bottom plate were also compared with the numerical simulation results. Numerical simulation results regarding to dynamic response of the cylinder corresponded well with experimental results. Discussions are given to boundary effects on behavior of explosion bubble and offset distance effects on response of the cylinder.

著者

黒田 貴子 大橋 訓英 原口 富博

出版者

社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.18, pp.39-44, 2013 (Released:2014-03-06)

参考文献数

9

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The vessels with waterjet propulsion system increase with the rapid growth in numbers of high speed vessels. It has been increasing when waterjet vessels do towing work. However, the towing performance of waterjet vessels has not been researched clearly.The purpose of this study is to investigate the towing performance of waterjet vessels. Bollard pull test and 2 ways towing tests which are towing ahead and astern were carried out by using the patrol vessels with waterjet of Japan Coast Guard. In general, a standard tow force of propeller vessels is 1.0tf/100PS. However, it was found from the test results that tow force of waterjet vessels is almost half of propeller's one. The cause of drop of towing performance for waterjet is the flow separations at the inlet's lip part.Since the numbers of impeller rotations becomes high to the low ship speed during bollard pull and towing, and the inlet velocity ratio (IVR) which means the inlet velocity to the momentum velocity becomes 1.0 or more. Duct flow of flash type inlet on bollard pull and towing were computed by flow solver "SURF"developed by National Maritime Research Institute. On the basis of those computed results, the loss due to the waterjet duct and the head of propeller and waterjet were evaluated and were compared with the towing test data. Comparison of computed results with test data shows good agreement. The results indicate that towing performance of waterjet can be estimated by evaluating the loss due to the waterjet duct.

著者

Takefumi Higaki Hirotada Hashimoto Hitoshi Yoshioka

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.36, pp.137-148, 2022 (Released:2023-01-31)

参考文献数

32

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Automatic collision avoidance is of significant importance to prevent maritime collisions. Although many studies have been conducted in recent years, autonomous system has not completely replaced human captains since it is still difficult to imitate their complicated decisions. Thus, the present paper tries to investigate and imitate experienced captains' maneuver using maximum entropy inverse reinforcement learning (MaxEnt IRL). We firstly verify that MaxEnt IRL can reproduce appropriate reward function from demonstrative trajectories. Afterwards, we conduct an experiment on a simulator where well-experienced captains maneuver in congested sea and estimate reward from the trajectories. Searching the route which maximizes the obtained reward, finally, we demonstrate the optimized route can avoid collision against multiple ships in compliance with the International Regulations for Preventing Collisions at Sea (COLREGs).

著者

安齋 圭祐 日野 孝則 山内 豊 水野 滋也

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.35, pp.1-12, 2022 (Released:2022-09-07)

参考文献数

22

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This paper describes the hull form optimization method of an icebreaker. In this optimization method, hull forms are generated by the original method we develop. The objective functions to be minimized are ice resistance in level ice and wave making resistance in open water. A multi-objective genetic algorithm is adopted as a numerical optimizer. We optimize a hull form which has the same hull form parameters as the preliminarily designed hull form for an application example. The optimization result provides many hull forms which have different balances of both objective functions as the Pareto solutions. It is found that some hull forms have better performance both in ice and open water conditions than the preliminarily designed hull form. We can develop an icebreaker hull form efficiently using the present optimization method.

著者

林 昌奎

出版者

公益社団法人日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

no.8, pp.61-69, 2008-12

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Sea surface waves had been observed remotely by using a continuous wave (CW) X-band microwave Doppler radar at off Hiratsuka of Sagami-bay. A new algorithm was applied to retrieve a sea surface elevation from the radar output Doppler signals. The sea surface waves observed by the microwave Doppler radar have been compared with the sea surface waves measured by the supersonic wave height meter. There were good correlations in both wave height and wave period between the waves observed by the microwave Doppler radar and measured by the supersonic wave height meter. The correlation of wave height was better than that of wave period. The microwave irradiation width on sea surface does a role of space filter. It seems that the filtering effect is a kind of low pass filter involving aliasing, the energy of short wavelength waves move to low wave number region. The algorithm to retrieve a sea surface elevation is described by the relation of the water surface profile and the orbital velocity of water particle on water surface that generated by water surface waves. A linear superposition method has been used to retrieve sea surface elevation. No empirical parameters are used in the algorithm. The water surface profile can be obtained from the water particle velocity on water surface by using the mathematical relation of the water surface profile and the orbital motion of water particle. Water particle motion on sea surface is affected by sea surface wind, currents, and sea surface waves. Water particle motion generated by sea surface waves can be separated by the difference of the fluctuation scale of each physical process.

著者

鈴木 啓介 佐久間 俊

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.11, pp.51-59, 2010 (Released:2011-01-28)

参考文献数

9

被引用文献数

1

---

When a high speed vessel is designed, it is important how we make her sectional area curve effectively on purpose to minimize the hull resistance. But on a sectional area curve, there are, in general, some constraints caused by the requirement of ship arrangement and we cannot reject them simply because we must build not only a small resistance ship but also an easily operable ship. A sectional area curve under these constraints is usually made from the experience of designers by referring one of a type ship, but we don't think we can get a true optimal curve easily only by the experience.In this report, we introduce the linear wave-making resistance theory into the optimal problem and Series 64 model 4793 is chosen as the object for analysis. The sectional area curve of Series 64 model 4793 is expanded into Mathieu function series and the performance is evaluated from the viewpoint of the wave-making resistance. Then we make the optimal curve for the improved hull form theoretically using calculus of variation under some constraints which are established artificially by us.Finally, we carry out resistance experiment of the improved hull form to evaluate our optimal method and it shows good result that the residual resistance of improved hull form becomes around the half of that of the original hull form.

著者

中村 昌彦 浅川 賢一 百留 忠洋 川谷 哲也

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.18, pp.143-156, 2013

被引用文献数

1

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A prototype of a 3000m-class underwater glider for virtual mooring is being developed by JAMSTEC (Japan Agency for Marine-Earth Science and Technology) with RIAM (Research Institute for Applied Mechanics) of Kyushu University. The vehicle houses an observation equipment and glides back and forth between the sea surface and the seabed collecting ocean data in a specific area (virtual mooring area) for more than one year.This paper summarizes the design concept and an outline of the glider and shows the results of the gliding tests in a towing tank.

著者

新井 洋 土井 康明 中島 卓司 陸田 秀実 三好 潤

出版者

社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.9, pp.55-62, 2009 (Released:2009-10-08)

参考文献数

9

被引用文献数

7

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The objective of the present study is to elucidate the ow mechanism of delaying stall by use of wavy leading edges. Experiments were carried out to examine the effects of variant wavy leading edges attached on NACA0018 section wing of aspect ratio 1.6. The Reynolds number based on the chord length is Rec = 1:38 × 105 for the experiments. For these tests, lift, drag, and moment of wings with and without wavy leading edges were measured in a circular water channel. Flow visualization on the surface of wings was also conducted in order to clarify the eects of the wavy leading edges on the delaying stall. It is found that the wavy leading edges can control ow separation and delay stall, which in turn is good for producing large lift force at poststall angles of attack. Under the same height condition, the short width of wavy protuberance shows good performance of the wings compared with that of the long width. The wavy protuberance located near the wing tip does not enhance hydrodynamic performance.

著者

稗方 和夫 大和 裕幸 リー チー 井上 守正 田中 和哉 小葉竹 泰則

出版者

公益社団法人日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

no.7, pp.97-106, 2008-06

被引用文献数

1

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A methodology to identify crucial tasks of ship design process is proposed in the first report. Crucial tasks of ship design process are identified in the standardized manner to support design knowledge transfer. In this paper, the proposed methodology is implemented as a web based questionnaire system to conduct a large questionnaire-based survey in design department of a shipyard. Unstructured interview after a questionnaire-based survey exhibited the essential characteristics of crucial tasks identified by the methodology. The characteristics in this paper are following three items: Trade-off such as amount of steel product and man hour, capability to extract 3D model and communication skills with outside of his/her team. The survey also pointed out some part of crucial tasks are outsourcing in Japanese shipyards. The proposed methodology is verified in this large empirical study.

著者

稗方 和夫 内藤 紀彦 大和 裕幸 安藤 英幸 中澤 崇

出版者

公益社団法人日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

no.2, pp.131-137, 2005-12

被引用文献数

5

---

It's getting more important to transfer knowledge from elder experts to young engineers especially in shipbuilding industry in Japan. We developed knowledge transfer system based on UT-ESS (University of Tokyo Educational Software for Shipbuilding) and proposed a method to acquire knowledge of elder experts using the developed system. The system describes design process as workflows and design documents are associated with tasks in workflows. The association between design process and design documents is described by metadata based on semantic web technology. The proposed method is evaluated through a case study of knowledge acquisition in basic design department in four shipbuilding companies.

著者

新郷 将司

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.22, pp.15-20, 2015 (Released:2016-02-29)

参考文献数

7

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This is the second paper of preliminary hull form planning for Non-Ballast Water Ship (NOBS) and Minimal Ballast Water Ship (MIBS). In the previous paper, the author proposed some simple procedures to estimate propulsive performance for NOBS/MIBS. In this paper, the author shows usability of these procedures to investigate preliminary hull form planning for NOBS/MIBS through carrying out some trial designs for VLCC. The trial designs reveal a relationship between principal dimensions and propulsive performance of NOBS/MIBS. In addition, CFD technique is used to estimate propulsive performance of Conventional Ship and NOBS/MIBS in the full load condition. The accuracy of CFD results is confirmed by comparing CFD results with results of towin g tank tests. At the stage of running CFD simulation, an initial hull form is required to generate grids. The author proposes a practical method for making an initial hull form of NOBS/MIBS. The initial hull form of NOBS/MIBS also can be used at the further desig n stage.

著者

Yeyes Mulyadi Eiichi Kobayashi Nobukazu Wakabayashi Trika Pitana Wahyudi Eko Prasetyo

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.20, pp.173-183, 2014 (Released:2015-02-26)

参考文献数

27

被引用文献数

2

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Recently, many subsea pipelines have been developed in busy port areas, including industrial ports, recreational areas, fishing areas, and other port facilities. Under busy ship traffic conditions, these subsea pipelines are likely to be exposed to the risk of damage by a dragged anchor or other dropped objects. In this paper, a model is proposed to estimate the dragged anchor accident frequency on subsea pipelines based on the concept introduced by Fujii. The proposed model is approached by estimating the number of dragged anchor candidates on subsea pipelines, Na, based on an analysis of the anchor stopping distance in a critical subsea pipeline area. The causation probability Pc is estimated using a Bayesian network method that is modified from the model of Det Norske Veritas (DNV) and Hanninen. Various factors are considered to estimate Pc, including the human factor, weather factor,technical factor, and support factor. Automatic Identification System (AIS) and Geographic Information System (GIS) data are combined to estimate the lateral probability distribution of the ship traffic around a subsea pipeline area. A case study of anchors dragging on the subsea pipeline in the Madura Strait of Indonesia is performed to demonstrate the implementation of the proposed model. The proposed model is validated by comparing the results for the estimated dragged anchor accident frequency on the subsea pipeline using the proposed model with the actual accidents recorded in the Madura Strait. The results of this validation analysis show that there is reasonable agreement.

著者

安川 宏紀 平田 法隆 浮田 寛之

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.17, pp.49-56, 2013 (Released:2014-01-17)

参考文献数

9

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This paper presents a practical simulation model for ship launching taking the dynamic coupling effect of trim angle change and vertical motion into account. The motion equations were derived in three stages of sliding, lift by stern and afloat modes in launching. By solving the motion equations in three stages continuously, ship speed change, trim angle change, traveling distance, pivoting load, etc. during launching can be calculated. To obtain the validation data of the simulation method, a fullscale test was carried out to measure the ship motions during launching by a Kinematic GPS (KGPS) system. Then, three antennas for KGPS were arranged on a Chip Carrier with 191.5 m in ship length. Some parameters needed for the simulation were determined by comparing with the fullscale test result. The present simulation method is useful for capturing th ship launching behavior.

著者

大久保 友結 満行 泰河

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.37, pp.115-123, 2023 (Released:2023-08-03)

参考文献数

18

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Shipbuilding is one of the most complex production systems in the manufacturing industry because of the incredible variety of parts and highly complex processes. However, production plans are currently prepared manually depending on the experience of expert workers. In this paper, a production planning method based on shipbuilding process simulation is proposed for use in actual shipyards, which simultaneously satisfies the needs of both production managers, who require on-time delivery plans, and field workers, who aim to minimize waiting time and improve operating rates. Specifically, the authors developed a hybrid method that combines backward and forward simulation for planning front-loading to meet deadlines and reduce waiting time. In the case study, the method was applied to a sub assembly conveyor line in an actual shipyard to demonstrate the validity and feasibility of the simulation results.

著者

青木 伊知郎 貴島 勝郎 古川 芳孝 名切 恭昭

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.3, pp.157-165, 2006 (Released:2006-12-26)

参考文献数

9

被引用文献数

5 4

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Since International Maritime Organization (IMO) has adopted "The Standards of Ship Maneuverability" as IMO Resolution MSC.137(76), the ship maneuverability is evaluated under this standard. Therefore, we have to know the accurate ship maneuvering characteristics at the design stage, especially the initial design stage. On the prediction method of ship maneuverability, there are many papers for estimating method of the maneuverability of a ship based on the model test, but there are few papers for predicting the maneuverability of a full-scale ship practically. The authors have already proposed the simple, accurate and practical prediction method for the ship maneuverability of model ship. So, we need to develop the practical prediction method for ship maneuverability of a full-scale ship in the deep water. In this paper, we propose the approximate formula of the interaction coefficient, γ and ωR0, obtained by comparing the predicted maneuvering motion with the measured results of the sea trial for twelve full-scale ships. We confirm the effectiveness of the practical prediction method using the approximate formula of the interaction coefficient for ship maneuverability of a full-scale ship. Though this approach must be validated in many kinds of ship as the next step, it will be expected that this method is very useful for predicting ship maneuvering characteristics at design stage on conventional ship.

著者

豊田 和隆 永田 修一 今井 康貴 瀬戸口 俊明 小野 圭介

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.13, pp.67-74, 2011 (Released:2011-09-08)

参考文献数

7

被引用文献数

2 1

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Fixed type pendulum wave energy converter is a kind of movable body type wave energy converter and it was invented by Kondo with Muroran Institute of Technology in Japan. Some researches on this device were carried out experimentally and theoretically, and its high energy conversion efficiency was shown. However, this device was not practical used yet, because the initial cost is so expensive as it needs heavy construction in the sea. And also, it is difficult to keep it safety under the critical weather condition like a typhoon is another main reason. So, as a solution strategy for above problems,Furusawa proposed the uplifting type pendulum wave energy converter. Furthermore Watabe proposed the floating type pendulum wave energy converter (FPWEC) which is moored to the seabed with some lines as another solution. Changing from fixed type device to floating type device, we can expect the reduction of initial costs and emergency measures. Watabe carried out some research on FPWEC, but it is not enough to say that the design method for this device was established.In this paper, we have made a test model of FPWEC for tank test and some tests were carried out as a first step of development for this device.To estimate the performance of this device, we have measured power output and body motion in regular waves.

著者

有吉 友和 加藤 直三 鈴木 博善 安藤 義人 鈴森 康一 神田 岳文 遠藤 聡

出版者

公益社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.5, pp.15-25, 2007 (Released:2007-09-11)

参考文献数

35

被引用文献数

3 2

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This paper describes the developments of new pectoral fins made of elastic materials with the functions of flexibility and multifunctionality for biomimetic underwater vehicles to use as not only a propulsive device, but also other applications such as grippers, avoiding damages to environment by rigid fins. We developed two types of elastic pectoral fins, an actively controlled pneumatic fin and a passively controlled flexible fin in this study. We carried out the verification tests for generating the propulsive forces and FEM analyses of the behaviors of two elastic pectoral fins.