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発行日: 1991/09/25
公開日: 2018/04/01
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原稿種別: 目次
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発行日: 1991/09/25
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原稿種別: 目次
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発行日: 1991/09/25
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原稿種別: 付録等
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発行日: 1991/09/25
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福嶋 祥人, 釘宮 了, 西本 仁, 塙 友雄
原稿種別: 本文
p.
1-13
発行日: 1991/09/25
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The authors created the concept to restrain the Non-uniform Flow around hull, so as to relieve the wave making Phenomenon on the small L/B vessel. The concept has been applied to the hull of wide breadth high speed vessels (Fn-0.38) with twin propellers and twin rudders. In order to confirm the high speed ability and fuel saving effect of this new type hull forms which are similar to so-called Trimarans, and to clarify the design problems involved, the authors repeated the trial design and tank test, that is, three (3) kind of new hull forms and one (1) ordinary hull form have been tested in circulating water channel with 2m length models, Finally the best performance hull form has been tested in towing tank with 5m length model. As a result, it was confirmed that this new type hull form is expected the speed up of 1.6 knots with same output, or the fuel saving of 38% with same dead weight and same service speed, as compared with the ordinary hull form.
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別所 正利, 佐野 靖彦
原稿種別: 本文
p.
15-26
発行日: 1991/09/25
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The preceding two reports deal with the optimization of high speed boat hull forms in regard to their wave-making resistace theoretically. These studies are founded on the presupposition that the linear theory may predict experimental results fairly well in high speed range. However, this presupposition has not been established on wide and general obserbations. The present report proposes the one of the basis of such presuppotion by comparing the residual resistance to the calculated wave-making resistance of the systematic series model tests Series 64 at David W. Taylor Model Basin. The results support well this presupposition in general but it seems that the residual resistance includes a component other than wave-making one at very high speed. The wave-making resistance at higher speed than the last hump is controled by the diverging wave components, so that shape of the transverse section may play a decisive role on the wave-making resistance. This is a different point at low speed case in which the transverse wave components play a decisive role and the sectional area curve determines nearly the wave-making resistance.
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馬場 信弘, 姫野 洋司, 谷川 和男, 鹿取 覚
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p.
27-34
発行日: 1991/09/25
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Numerical experiments are carried out to examine the accuracy and convergency of numerical solutions by the optimization method developed in the preceding paper for obtaining a body profile with minimum viscous drag. The nonlinear programming technique based on the modified feasible direction method was incorporated into the time-marching procedure for numerical solution of the incompressible Navier-Stokes equation. Some improvements were made on the discretization scheme of the governing equation and boundary conditions and on the implementation of the constraints associated with the optimization problem. The finite-difference solution of the Navier-Stokes equation shows weak but persistent unsteadiness which may give rise to large error in finding the usable feasible direction in the time-marching procedure. Applying the finite-volume formulation with geometric conservation, on the other hand, possibly reduces the error due to the unsteadiness to a satisfactory level. The results of numerical experiments indicate that the gradient of viscous drag with respect to the deformation of body profile dep ends on the computational resolution as well as the deformation increment. It is concluded that the relative accuracy in evaluating the gradient of drag required for finding the feasible direction is one of the most important factors of the successful convergence to the optimum solution. The improved results computed within the relative accuracy of 0.1% suggest again that one of the optimum solutions at the Reynolds number of 100 is an asymmetric profile of the fore and aft parts quite different from those obtained in Stokes and Oseen flows.
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薮下 和樹, 斉藤 実俊, 戸田 保幸
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p.
35-42
発行日: 1991/09/25
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Numerical computation of two-dimensional imcompressible flow was conducted around a finite flat plate. A full implicit scheme was used to solve the Navier-Stokes equations and a continuity equation. The three basic equations were descritized by finite difference method and the predictor-corrector method. The subsequent algebraic matrix was solved directly at the same time. The examples of the results were presented for the steady and unsteady cases at a Reynolds number 10^5. The latter case is the flow field around a flat plate in surging motion around a mean advance speed. The steady state solution was compared with the Blasius solution and the numerical solution of the triple-deck theory. The close agreements were obtained. With regard to the unsteady case, the solution is compared with Lin's analysis which assume the small amplitude and the high frequency of the unsteady motion. For the case in which Lin's assumption is valid, the numerical solution was in close agreement with the analysis. From these solutions, the present scheme has the ability to resolve the trailing edge interaction and the unsteady effect. For the unsteady flow, the solutions were also obtained for the large amplitude case and the medium frequency case. In the former, the small nonlinear effect to the averaged velocity was observed, where in the latter the large difference was observed for the fluctuation part.
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奥野 武俊, 成富 和士
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p.
43-49
発行日: 1991/09/25
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This paper describes the results of flow field measurements around a high-speed type fine ship model at incidence. The measurements were made by using a robot system for flow measurements in a circulating water channel with 5-holes Pitot Tube. A number of velocity data were obtained in both face and back side region of the ship, and around the skeg. The detailed measurement and analysis around skeg at stern shows that the physical structure of the separated vortex from skeg in the back-side region is quite different from the vortex due to the bilge keel, which is the so-called typical longitudinal vortex.
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西尾 茂, 姫野 洋司, 高松 健一郎
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p.
51-64
発行日: 1991/09/25
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Uncertainly analysis (UA) is applied to the resistance and self-propulsion tests of a ship model, in which the problem of measuring object, the treatment of low-pass filter, the problem of curve-fitting process, etc. are dealt with. The present paper also corrects some parts in the authors' previous paper on the UA for resistance test, and applies the method further to propeller-open and self-propulsion tests. The importance of choosing appropriate object item for uncertainty analysis, i.e., time-mean or instantaneous value, is emphasized. Authors evaluate a new error term S_F in curve fitting process, as well as the standard estimated error SEE. And a consideration is made on the error and its propagation when a low-pass filter is installed in the measuring system. Examples of UA are shown in tables and figures, in which error sources, estimated errors, their propagation route, and sensitivities to the UA items are listed and illustrated. Although the value of the errors themselves are not so small as expected, it is found that UA is quite useful for detecting dominant error sources as well as for obtaining the error values.
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大内 一之, 玉島 正裕, 新井 健太
原稿種別: 本文
p.
65-73
発行日: 1991/09/25
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PBCF (Propeller Boss Cap Fins) which is composed of small fins attached to propeller boss cap was proposed as a novel energy-saving device, and propeller efficiency gain by PBCF has been confirmed through many kinds of model tests and actual sea trials. Currently more than 100 PBCFs are attached to full scale propellers and also demonstrating the effect of eaergy saving. This paper describes the study on cavitation pattern of propeller with PBCF and the effect of PBCF on the noise generated by propeller through the model experiment in cavitation tunnel. The results obtained were as follows; (1) PBCF extinguishes hub vortex cavitation thoroughly but hardly influences on the cavitation generated on blades or tip vortex cavitation. (2) PBCF reduces 3 to 6 dB of sound pressure level of propeller in the range of over 25KHz in the experiment. These results lead us to believe that PBCF is also effective on reduction of propeller noise.
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高木 又男
原稿種別: 本文
p.
75-84
発行日: 1991/09/25
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This paper gives the mathematical proof of the equality of the integral representations and the multipole expansions (series representations) of the velocity potentials in ship motion theory in the cases of two-dimensional (with advance speed) and three-dimensional (without advance speed) problems. The coefficients of the series are represented in terms of the source distributions in the integral representation.
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吉田 尚史, 斎藤 公男
原稿種別: 本文
p.
85-91
発行日: 1991/09/25
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Eigenfunction expantion method is applied to the radiation problem on water of finite depth. In this paper, vertical oscillations of the floating body are considerd. Numerical calculations were made for three types of body shape such as a half immersed circular, a Lewis form and a rectangular cylinder. The results for a circular and a Lewis form cylinder show relatively good agreement compared with other methods. On the other hand, in case of rectangular cylinder the correspondence is not satisfactory and further investigations are needed.
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笠原 昭夫, 前田 久明, 増田 光一, 吉野 博之
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p.
93-99
発行日: 1991/09/25
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There has recently been an interest in the methodology for synthesizing multi-directional random sea states. Several authors have reported that the wave generator was derived for both single and double summation models of the wave generation. To simulate irregular waves with directional spectrum, the authors studied the characteristics of directional waves generated in two models numerically and experimentally. Various alternatives for generating the fundamental wave trains areinvestigated through numerical simulation and results do not show differences between single summation and double summation wave model.
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菊 孝志, 大塚 耕司, 池田 良穂
原稿種別: 本文
p.
101-109
発行日: 1991/09/25
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It was found by Chaplin and the authors that the wave forces acting on cylinders horizontally submerged in regular and irregular waves dramatically decrease with increasing Kc number in very low Kc number region (1<Kc<3) due to vortex shedding. In the present paper, the effect of the current over a circular cylinder on the reduction of the wave forces is experimentally and theoretioally investigated in regular waves. The experimental results of the force measurements show that the inertia forces and drag forces acting on the cylinder are significantly affected by the current, direction and speed. The vortex shedding pattern is also investigated through simulations by the discrete vortex method and flow visualizations.
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池田 良穂, 芳山 朋史
原稿種別: 本文
p.
111-119
発行日: 1991/09/25
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In this paper the coupling effect on the peformance of a Flume type anti-rolling tank is experimentally investigated. The results of a bench test of an anti-rolling tank including the effect of sway motion as well as roll motion demonstrate that the sway motion reduces the reduction of the roll angle by the anti-rolling tank and lengthens the natural period of the tank.
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高木 健
原稿種別: 本文
p.
121-128
発行日: 1991/09/25
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In order to calculate the added resistance in following waves, Maruo and Iwase's simplified formula for the calculation of the added resistance in waves is improved. Applying their assumption, simplified formulas for the calculation of the wave induced steady lateral force and turning moment are developed. The singularity distribution for the calculation of the wave induced steady forces on the assumption of the slender body is investigated and the importance of the continuity at the end point is shown. Some numerical results by simplified formulas are compared to the exact solution. The precision of numerical results by simplified formulas are good enough for the practical use.
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梅田 直哉, 有路 実, 山越 康行
原稿種別: 本文
p.
129-138
発行日: 1991/09/25
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The authors had proposed a theoretical method for calculating probabilities of capsizing due to pure loss of stability for a ship running in quartering seas in their previous report. In this report, their method was verified by the Monte Carlo simulation in time domain. That is, the capsizing probabilities predicted by the proposed method are slightly larger than those given by the Monte Carlo simulation. We used a simplified numerical model to obtain time series those are sufficient for statistical analyses. The model treated two degrees of freedom, namely, surge and roll and took the non-linear restoring moment due to a wave and a roll angle into account as well as wind forces, wave exciting forces and so on. Resistance, propeller thrust and roll damping moments were predicted by model experiments. Repeating numerical runs with common wind and wave spectra and different phases, we obtained the probability of capsizing of a small trawler in quartering seas. In addition, all simulated capsizings were occurred when the ship was situated on a crest of a wave. Immediately before the capsizings, the ship suffered synchronized roll motion or not as the case may be. This capsizing mode coincides with the mode assumed in the proposed theoretical method for capsizing probabilities.
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山本 修, 北村 泰弘
原稿種別: 本文
p.
139-143
発行日: 1991/09/25
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Effect of hull form above water plane is studied on vertical ship motions. Ship motion test in regular head wave is carried out with use of series model ships, which have different breadth and different bow profile above water plane. The breadth above water plane varies from 100% to 40% of maximum water breadth. Result of the ship motion test shows that the vertical ship motions become small depending on reduction of the breadth of model ship above water plane. Furthermore vertical forced oscillation test and wave exciting force measurement are carried out with use of the 55% breadth model ship. Results of these experiments show that radiation forces and wave exciting forces acting on the model ship are fully nonlinear against the amplitude of forced oscillation and the incident wave amplitude.
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梶 正和, 西 義和, 山上 順雄
原稿種別: 本文
p.
145-151
発行日: 1991/09/25
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Hydrofoil vessels, which are supported partially or totally by the foil lift, have been widely investigated. Accurate estimate of the unsteady lift acting on the foil is important to predict vessel's motion on the wave. This paper presents the theory of the unsteady lift acting on oscillating three dimensional hydrofoil submerged under a free surface and the numerical calculation results. The method of images is employed to account for the free surface and a formula is derived on the assumption that ratio of span to average chord (aspect ratio) is not too small. The validity of this theory is confirmed on account of good agreement of experimental values and theoretical ones. As a result of calculating the unsteady lift of the three dimensional hydrofoil in various conditions, the relations between the characteristics of the lift and the submerged depth, aspect ratio, and reduced frequency respectively are made clear.
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内藤 林, 相良 聡
原稿種別: 本文
p.
153-164
発行日: 1991/09/25
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As a ship speed becomes faster, the configuration of a ship has been changing to keep high seakeeping performance in waves. A hydro-wing system is one of the choice which can support the whole or a part weight of a ship. It is necessary for comfortableness of passengers to maintain the constant vertical force acting on the hydro-wing under wave conditions. The characteristics of the hydro-wing with flap in waves is investigated with model experiments and theoretical considerations. Especially we pay attention to reduce a fluctuation of vertical force acting on the hydro-wing in waves by using the flap. As result of the research, it has been cleared that the fluctuation of vertical force in waves can deal with quasi-steady assumption under the usual condition. One method is investigated to control the vertical force acting on hydro-wing by using forcasting attack angle to wing which angle is estimated with wave profile at the ahead of the hydro-wing.
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織田 博行, 大津 皓平, 佐々木 学, 関 佳之, 堀田 敏行
原稿種別: 本文
p.
165-173
発行日: 1991/09/25
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In the conventional roll stabilization system, fins or anti-rolling tank has been utilized as the actuator. However, it does not furnish the function to keep the ship's course. On the otherhand, some researchers have concentrated on the study of rudder roll combined motion since 1970's and the development of the autopilot system for rudder roll stabilizatin since 1980's. The first part of this paper will be devoted to examine the feasibility of the rudder roll stabilization by statistical analysis of the data which were gained by full scale experiment. Based on these results, the authors propose a Rudder Roll Control System (RRCS) to control not only yawing motion but also rolling one simultaneously, using the modern optimal control theory. In this system, a multi-variate auto regressive model of the rudder, roll and yaw motion are fitted to the actual data which were obtained by a full scale ship's experiment and the optimal control gain under appropriate evaluating function are calculated. In the last part of this paper, the authors will report the results of the simulation to assess the effect of control and the full scale experiments by a small training ship.
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烏野 慶一, 松野 二郎, 伊藤 智行, 五十嵐 和之
原稿種別: 本文
p.
175-183
発行日: 1991/09/25
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The authors had pursued the mathematical model of hydrodynamic forces acting on ships moving in an oblique direction. This model could separate the fluid force from the following forces; ideal force (Munk moment), lift and induced drag forces due to viscosity, cross flow drag and lift forces, as well as the frictional drag force. In the paper referred to above, the mathematical model had a good agreement with measured forces and gave the physical meanings in terms of fluid dynamics. However, in some cases the model could not describe the stall effects with reasonable physical meanings in terms of fluid dynamics. This occurred in the case where the stall effects decreased the lift effect and did not start in the stage of small drift angles. In order to solve this problem of unreasonable stall effects, this paper adopted the cross flow drag coefficient C_D=C_<D90>・∣sinβ∣・(1+P・cos^2β) instead of C_D=C_<D90>・∼sinβ∼, and analysed forces mainly using longitudinal force when taking into account of reasonable stall effects in stead of the lateral force. As the result, the authors generated the following mathematical model. [numerical formula] where [numerical formula] and U:ship spped u':longitudinal component of speed (=u/U=cosβ) without dimension v':lateral component of speed (=v/U=-sinβ) without dimension m'_x,m'_y:added mass coefficients without dimension C'_<LAB>:coefficient of lift force due to ship's fore-aft asymmetry C'_F:coefficient of longitudinal resistant force C'_L:coefficient of viscous lift force C'_<Di>:coefficient of induced drag force ΔC'_L, ΔC'<Di>:coefficients of stall C_<D90>':coefficient of cross flow drag at β=90°l_<v0>:longitudinal center of viscous lift force from midship l_<i0>:longitudinal center of induced drag force from midship p:anothecoefficient of cross flow drag m'_0, m'_1:moments of lateral projected area of ship about midship
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湯室 彰規
原稿種別: 本文
p.
185-194
発行日: 1991/09/25
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In the present paper, a simplified method for calculating the maneuvering hydrodynamic forces on a ship's hull moving parallel to a single side wall in shallow water is developed using the linear lifting surface theory. Calculated results agree approximately with the experimental results obtained by changing distance between the ship and the wall, and water depth. In order to clarify nonlinear characteristics of hydrodynamic forces on a ship caused by presence of a side wall, a basic calculation concerning hydrodynamic forces on a flat plate wing inclined to wall surface is examined. By using the image method, the calculation is made for the wing inclined at a large angle of attack in the proximity of a wall plane, based on Bollay's nonlinear wing theory. Experimental results indicating unsymmetrical variation of hydrodynamic forces with positive or negative angles of attack, can be explained well by the theoretical values. Furthermore, experiments on interaction forces between two ships were performed by employing slender-body ships. Calculated results obtained through the method, which was used for tnaker-typed ships in the previous paper, agree qualitatively with the experimental results.
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浜本 剛実, 本田 啓之輔, 石川 隆浩
原稿種別: 本文
p.
195-200
発行日: 1991/09/25
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In stopping maneuvers, a ship may deviate from a straight path due to the loss of directional stability and the side force induced by propeller revolution. In this paper, the authers present a practical mathematical model that can be used to calculate the track reach by taking into account the longitudinal component of centrifugal force acting on a ship during stopping maneuver with turning motion. Full scale stopping maneuver trials are carried out for a traning ship with controllable pitch propeller. The results of full scale trial are compared with the results computed by both the present model and the traditional one for discussion.
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高川 真一, 難波 直愛, 森鼻 英征, 手塚 久男, 前田 逸郎, 重国 清, 石黒 慎二
原稿種別: 本文
p.
201-207
発行日: 1991/09/25
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Deep Submergence Research Vehicle "SHINKAI6500" is the latest manned research vehicle which can dive to the deepest existing in the world. The maneuverability of a submersible vehicle is highly dependent on its cofiguration. During the development of "SHINKAl6500" we have assumed great importance to its decending and ascending capability. "SHINKAI6500"'s configuration has been improved in various respects reflecting "SHINKAI2000"'s operation results, finally determined based on the results of twice wind tunnel tests and a tank test. In sea trials it is confirmed that hydrodynamics resistance of "SHINKAI6500" is remarkably reduced compared to that of "SHINKAI2000". This paper describes the outline of these model tests, sea trials and the process of the development of its streamlined cofigulation.
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高木 健, 小田 晴信, 内藤 林
原稿種別: 本文
p.
209-215
発行日: 1991/09/25
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This paper presents the methodology for construction of the most suitable system for the deep sea manganese nodule mining. The system consists of Miner, Mining Ship, Transportation Ship and Metallurgical Processing Factory. As the objective function, the period of the revulsion of capital is chosen. The reliability of the results is investigated by varying the costs of operation, the ship prices and metal prices. The optimum system for the mining and transportation is obtained, which the system includes the effect of ship motion in waves on the operation days. The period of the revulsion is mostly affected by the price of manganese nodule and the acceleration of ships.
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梅崎 一夫, 小林 幹弘, 幸川 寛志, 水野 博介, 西村 信一, 岡安 孝行, 柳 和久
原稿種別: 本文
p.
217-223
発行日: 1991/09/25
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One of the most difficult tasks in designing a passenger ship is to make it vibration free while keeping the hull structure very light for stability reasons. In order to accomplish this for the 23,000 GT cruise ship shown in Table 1, special attention was paid to the alighnment of structures during layout design, and analyses and experiments of vibration were carried out through every stages of design and construction. This paper describes outlines of these tasks and examinations. The major contents are: -Arrangement of anti-vibration walls -Center core structures -Vibration analysis results -Exciter test results -Full scale measurement results -Effect of phasing of main engine revolutions
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岡田 博雄, 山本 浩志, 中津 健治, 室津 義定
原稿種別: 本文
p.
225-230
発行日: 1991/09/25
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This paper is concerned with the ultimate strength and reliability analysis of frame structures. The multiple surface approximation for the failure condition of an element is first introduced, which takes account of the nonlinear plasticity codition under biaxial bending moments and an axial force. The failure condition facilitates the more accurate calculation of failure probabilities through the automatic generation of ultimate collapse modes. The so-called branch-and-bound method is applied to select the probabilistically dominant failure modes. Finally, the proposed method is applied to a plane framework under in-plane and out-of-plane loads. Through numerical example, the applicability of the proposed method is demonstrated.
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岩田 節雄, 山脇 義朗, 田中 敬子
原稿種別: 本文
p.
231-238
発行日: 1991/09/25
公開日: 2018/04/01
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Generally, a doubling plate has been used as an equipment support member. In designing the doubling plate, designers have to pay the particular attention how to decrease the stress concentration, but there are no official rules and no standards. In the present paper, the theoretical an analysis has been performed by finite element method. As the results of our investigations, followings can be concluded. (1) The doubling plate gives an appreciable influence on the structural stress concentration under the longitudinal bending stress. (2) HT steel need not be chosen for the doubling plate.
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島本 幸次郎, 松山 千秋, 竹澤 節雄
原稿種別: 本文
p.
239-246
発行日: 1991/09/25
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The thrust force on electro-magnetic proplusion ship is generated by lorentz force due to interaction of the magnetic field and electric current in sea water, and an application of superconducting magnets are proposed in order to obtain heigher magnetic field. Initiated by Ship and Ocean Foundation in 1985, the research and development have been applied on superconducting coil, electrode, liquid helium refrigerator, hull form, etc. and a full scaleexperimental ship is now under construction, on which the thrusters of superconducting electromagnetic propulsion are installed. In this paper, the initial design of the ship, the principle of the propulsion, main technical points of the thruster and the propulsion system of the ship are described including their test results etc.
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原稿種別: 付録等
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App2-
発行日: 1991/09/25
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原稿種別: 表紙
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Cover2-
発行日: 1991/09/25
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