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Akira Yoshitake, Katumi Kataoka, Jun Ando, Kuniharu Nakatake
Pages
1
Published: 2002
Released on J-STAGE: June 30, 2003
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In this paper we present experimental data of wavemaking resistance of catamaran and trimaran. We adopt the Wigley catamaran and trimaran for the present experiment. Main hull is a usual Wigley model and the outrigger is a half Wigley model which is a model halved at the center plane. In the experilment at the towing tank of Kyushu University, we measured total resistance of each hull at a fixed lateral distance by changing the stagger and Froude number. From measured total resistance, we obtain the residuary resistance coefficient. Numerical calculation based on Rankine source method is also performed. By experiment and calculation, we show the usefulness of the numerical calculation method and make clear the effect of stagger on the wavemaking resistance of catamarau and trimaran.
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Shigeru Hayashita
Pages
2
Published: 2002
Released on J-STAGE: June 30, 2003
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In order to investigate the scale effect of propeller shaft of high-speed craft, hydrodynamic forces acting on the prismatic body with shafts are measured by the load cell. One of shaft is rotated by the motor to investigate the effect of rotation. Measured lift and drag coefficients of shaft are almost the same as ones of smaller shafts which were reported in the previous paper. The scale effect and the effect of rotation of shaft on hydrodyamic forces are small.
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Kunihide Ohashi, Nobuyuki Hirata, Takanori Hino
Pages
3
Published: 2002
Released on J-STAGE: June 30, 2003
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The applicability of the body force model which represents the contrarotating propellers(CRP) effects is examined. At first, the numerical simulation of the propeller open water test is carried out. The velocity distributions obtained by the numerical simulation are compared with those of the measured results and the validation of the model is performed. Then the numerical simulation of ship flows under self-propulsion condition is carried out. The wake flows behind a conventional single propeller(CP) and CRP are compared. The self-propulsion factor, the thrust deduction coefficient in particular, is compared with the measured data and the adaptability of the present model is discussed.
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Yoshihiro Kobayashi, Kunihiko Komura, Shin Okamura, Katsuhisa Yano
Pages
4
Published: 2002
Released on J-STAGE: June 30, 2003
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The diffusion and convection flow will occur concurrently in the CO
2 storage well by being induced from the ocean current and results in the CO
2 diffusion into the ocean. Authors studied these phenomena in the ocean and the horizontally connected sea bottom basin in which liquid CO
2 was sequestrated in about a partial depth. The geography of the sea bottom and its basin was approximated by three-dimensional shape. The characteristic properties and behaviors of CO
2 in seawater were taken into analysis. Finally the conceptual marine structures and installation procedures of the system for the restraints of diffusion into the ocean were discussed and proposed for further development in future.
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Hironori Yasukawa
Pages
5
Published: 2002
Released on J-STAGE: June 30, 2003
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A motion equation for a maneuvering ship in the proximity of fixed obstacle is derived within potential theory. The equation includes rationally added mass change and hydrodynamic forces such as bank suction force arising due to presence of the obstacle. Solving the motion equation, ship maneuverabilty in the proximity of non-uniform banks is simulated under the various initial conditions. Then, the added mass and the hydrodynamic forces are calculated using a 3D panel method under the assumption of rigid wall free surface in the time cycle where the motion equation is numerically solved. Hydrodynamic interaction between bank and ship is consistently included through such the procedure. The maneuvering motion for a ferry in the proximity of the bank is realistically demonstrated.
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Shun Sakuma, Takashi Kanemaru
Pages
6
Published: 2002
Released on J-STAGE: June 30, 2003
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It is important to know historical changes of some parameters for ship design in order to understand what naval architects have been required with the time. Yamaguchi et al. discussed recently the historical changes of merchant ship’s propulsive efficiency in detail and showed the progress of performance. This report shows the investigation of the historical changes of the naval ships in Japan. The parameters dealing with this report are stability, weight, volume and propulsive efficiency. As the result of this report, it is found that the change of propulsive performance is small, and the change of stability and ship’s density shows the design concept varies gradually from weight design to space design.
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Kohei Matsuo, Akiji Shinkai
Pages
7
Published: 2002
Released on J-STAGE: June 30, 2003
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This paper is concerned with procedures of making global wave information database derived from the observation from Radar Altimeter on satellites. Fundamental specification of ERS-2 satellite and characteristics of this product called ‘ALT.WAP’ are investigated. The procedure making wave statistical database which is convenient to the fields of naval architecture and marine engineering is proposed, and characteristics of this database are examined by comparing from other database derived from GEOSAT satellite and buoys. By using these wave data, application for long-term statistical prediction of the ship responses for a container ship is executed.
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Akiji Shinkai, Shinsuke Kosuge, Shunichi Egashira
Pages
8
Published: 2002
Released on J-STAGE: June 30, 2003
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This report is using the observation data based on an artificial satellite, and aims at considering formulization of the procedure in the case of conducting investigation of maritime conditions of the ocean space in which the ship carries out ballast water exchange. Taking the route of between Japan and Australia or the North America west coast for the example, we investigated maritime conditions using the long-term billow statistics data which the marine research satellite GEOSAT collected. When we perform various examination in the initial design of ship supposing the ocean space where ballast water exchange of ships is carried out, if the formulized procedure applies to the data of GEOSAT, we could conclude that a setup of maritime conditions could be performed efficiently and simply.
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Hisashi Numata, Masahiro Tamashima, Nobuyoshi Fukuchi
Pages
9
Published: 2002
Released on J-STAGE: June 30, 2003
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Ballast water and sediment discharge are currently pointed out the principal cause for the international introduction of non-indigenous aquatic species that exert an influence on environmental pollution to human and marine life beyond its historic range. A new method to exchange ballast water is proposed, in which clean water is guided from ship’s bow front and discharged out of bellmouth on the bottom of tank utilizing pressure difference around the hull surface of ship in forward motion. The idea does not require any pumping operation except for topping up water to initial water level. The test using model ship of 1/120 scale confirmed the exchange of water in a tank. The water exchanging rate is investigated using model ballast tanks of 1/50 scale for single and double hulled ships. The power loss and power consumption of pumping and total system are estimated on Aframax type of tanker and compared with those of the flow-through method. The power consumption of pumping of new system is about one tenth and the power consumption of total system is one fifth to those of the flow-through method.
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Shiro Kataoka, Akira Sueyoshi, Kiyoshi Arihama, Hidetsugu Iwashita, Mi ...
Pages
10
Published: 2002
Released on J-STAGE: June 30, 2003
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In this study a time domain computation method is applied to so-called the body non-linear problem in seakeeping. The computation method is applied to a modified Wigley model. Through the comparisons with experiments and other computation methods, the efficiency of the present method is confirmed. Computations for a variety incident wave amplitude are carried out for a modified Wigley model, and body non-linear effects which are caused by the change of the wetted surface beneath the still water are remarkably obserbed in hydorodynamic pressure but are not so remarkably for ship motions.
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Seiji Iwamoto, Takefumi Ishimatsu, Hajime Imanishi, Ryuzo Ueno
Pages
11
Published: 2002
Released on J-STAGE: June 30, 2003
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Two newly designed trawlers (Yamaguchi Maru No. 1 and Yamaguchi Maru No. 2) of 60 GT were completed in February of 2001 for use in the restricted trawl fishing area between Japan and Korea. In this trawl fishery, trawling is done with two boats working in tandem. The trawlers are presently doing various tests in the offshore fishery. We herein introduce the development concept of the new type trawlers built as models for the improvement of the offshore fishery in Yamaguchi Prefecture, compute the longitudinal motion (heave and pitch) of the trawlers in regular waves, and discuss these characteristics.
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Shuji Mizokami, Hironori Yasukawa, Masami Matsuura
Pages
12
Published: 2002
Released on J-STAGE: June 30, 2003
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Model experiments for a Post-Pamamax container ship were carried out in Multi-directional (short-crested) irregular waves. The condition of principal wave direction was head sea waves. The measurement items were ship motion, vertical bending moment and wave induced pressure. Experimental results in Multi-directional waves were compared with the results of uni-directional (long-crested) waves, which were carried out in advance. We checked on the effect on a ship’s responses caused by directional spectrum waves. Besides, numerical computations, by means of slender ship theory (Enhanced Unified Theory) were also carried out. The calculation results were compared with the experimental data to check on applicability. As a result, for ship motion and vertical bending moment, there is no significant difference between uni-direction waves and multi-directional waves. On the other for wave-induced pressure, the difference can be seen depending on wave condition and the position of measurement. The numerical computation results by EUT well predict tendency of experimental results.
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Hikaru Hoshi, Mikio Nose
Pages
13
Published: 2002
Released on J-STAGE: June 30, 2003
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Nagasaki Institute of Applied Science has developed CFRP float for human-powered hydrofoil. This float was far 4m, and complicated from product. High quality molding of such a product requires autoclave consolidatoin method. However, as exclusive equipment and cost necessary for autoclave consolidation method, float was molded by simple molding equipment. In development of simple molding equipment, improvement of circulation hot air inlet and outlet was important fruit. To prove the strength of float by simple molding equipment, static strength tests were conducted. As result, CFRP float with desired performance could be obtained.
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Junichi Katsuta, Kazuyoshi Kawano, Kentarou Fujii, Nobuhiko Shibata
Pages
14
Published: 2002
Released on J-STAGE: June 30, 2003
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In the previous report, the authors had proposed an estimating method of deformation using PC in the heat-bend process for ship hulls. In this method, the shape of heated plate model was calculated by the 3-dimensional elastic analysis, omitting heat conduction analysis and plastic analysis. In this study, we have reported in regard to the setting method of the imitative heating conditions in the imitative heat-bending simulator. The imitative heating conditions are obtained by heat conduction analysis with moving imitative heating area. The compelling displacements for simulation calculate from maximum temperatures of surface and back-face. And we have showed the simulated results of the saddle-shaped shells using imitative heating conditions. These heating conditions have brought about very good results.
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(Part 1, Simplified Evaluation of Natural Frequency for Double Bottom Structures)
Akira Katoh, Hiroshi Furuno, Fengxiang Yang
Pages
15
Published: 2002
Released on J-STAGE: June 30, 2003
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In case of study on hull girder vibration for the vessels having double bottom structures, it is well known a coupling effect of out-of-plane vibration on double bottom structures must be taken into account. In this paper, simplified evaluating method of the natural frequency for double bottom structures in initial design process is investigated. In previous paper, the authors have already proposed the simplified strength evaluation for the double bottom structures in consideration of shear deformation effects. The present paper is provided to estimate the fundamental natural frequency for double bottom structures with the various constraint conditions given by torsion beams on these boundaries. Through these studies, it is obtained that the proposed method is in practical use for the estimation of natural frequeney of double bottom structures because of good agreements with the results of finite element analysis.
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Kunihiro Hamada, Marcus Bentin, Mitsuru Kitamura
Pages
16
Published: 2002
Released on J-STAGE: June 30, 2003
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Master-Planning system to support production planning for cooperative assembling with several shipyards is discussed in this paper. In the research concerning shipbuilding CIM, methods to generate information for Change (Assemble) Operations from the Product Model are more focused than Transportation- and Storage Operations. However, these two are much more important in cooperative assembling. Therefore, information processing in production planning (especially generation process for Transportation- and Storage Operations) is managed, and new process models to generate operation models are introduced. Further, a new representation method for Operation Model that can express changes in forms, places and time is introduced. System configuration, details of operation model and its generation process are shown in the paper.
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Marcus Bentin, Kunihiro Hamada, Mitsuru Kitamura
Pages
17
Published: 2002
Released on J-STAGE: June 30, 2003
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The basic idea and implementation of a Master Planning Optimization System for cooperative ship assembling is introduced and its design variables are discussed. The optimization is carried out by a SGA that is connected to a Simulation System by the use of several developed controllers. These controllers need additional information usual Simulation Systems do not need. Further, the structure of the used chromosomes and its design variables are shown together with the used genetic operators. At this stage of the developed prototype, the Optimization System is limited to the optimization of the overall production time (makespan). Necessary information for the optimization process is discussed as well as the limits of the presented system by means of presented applications.
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Yasuhisa Okumoto, Kouhei Murase, Morinobu Ishiyama, Yukari Yamamoto
Pages
18
Published: 2002
Released on J-STAGE: June 30, 2003
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Though the assembly schedule of ship hull blocks is based generally on the erection sequence in the building dock, it is not always necessary to follow the erection order, because there is buffer area, stock yard of a block, between the assembly yard and dock usually. Therefore, in this paper, the assembly sequence of hull blocks was separated from the erection order, and the optimization was studied, considering the constraint of the block number stocked in the installation yard. An optimization program was developed to minimize the sum of the idle time in a tact time, since the tact system has been generalized in many shipyards at present. Backtracking method, a kind of branch and bound method, was applied for the technique of the optimization problem. As a result, it has been understood that the idle time can be decreased considerably by this simulation result.
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