Yasuo Yoshimura

Yasuo Yoshimura
Hokkaido University | Hokudai · Graduate School of Fisheries Sciences

Doctor of Engineering

About

174
Publications
23,470
Reads
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1,122
Citations
Citations since 2017
23 Research Items
737 Citations
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
Introduction
Naval Architect and Research on Ship Maneuverability
Additional affiliations
November 2017 - March 2021
The University of Tokyo
Position
  • Project reseacher
April 2016 - October 2017
The University of Tokyo
Position
  • Project Reseacher
April 2014 - present
Hokkaido University
Position
  • Professor Emeritus
Education
April 1975 - March 1978
Osaka University
Field of study
  • Naval Architecture
April 1973 - March 1975
Hiroshima University
Field of study
  • Naval Architecture
April 1969 - March 1973
Hiroshima University
Field of study
  • Naval Architecture

Publications

Publications (174)
Book
Full-text available
The knowledge on the ship maneuvering is indispensable for ship operators and ship designers. The ship maneuverability basically means the performance of motion response to rudder and/or propeller operation of a ship in calm water. This is represented as the following basic abilities: “moving straight”, “turning” and “stopping”. To be more precisel...
Conference Paper
Full-text available
The authors proceed from the approach of Mao's theory used in the previous report. In this study, The authors will develop the past results and theorems obtained for similar mechanical systems such as Arnold and Kozin. Then, they will study this system with the aim of clarifying the parameter area of system stabilization and re-stabilization due to...
Article
An equivalent single rudder (ESR) model is presented for maneuvering simulations of twin-propeller and twin-rudder ships within the framework of the maneuvering modeling group (MMG) method Yasukawa (J Marine Sci Technol 20:37–52, 2015). It eliminates the complexity of a mathematical model by treating a port and starboard rudders as a single rudder...
Conference Paper
Full-text available
Generally, the Lyapunov stability theory is used as a method for considering the stabilization of a control system. In this case, since the probability disturbance is added, we will consider it in the framework of the probability Lyapunov stability theory. Various examples of such studies have been studied so far. In addition, stabilization and des...
Article
Full-text available
If an unexpected load collapse occurs, a ship may heel. The ship must navigate safely in the heeled condition until the destination port is reached. In this paper, the turning performance of a heeled ship is investigated. Firstly, a free-running test is conducted using a pure car carrier model to capture the turning characteristics with a rudder an...
Article
The rudder force, including interference with a ship hull in large drifting conditions, is investigated in this study by captive model tests using a ship model with steering. In the tests, hydrodynamic forces acting on the ship, the rudder normal force, and propeller thrust are measured while changing the hull drift angle in the range of -180° to 1...
Article
Full-text available
A tank experiment using a flexible multi-column floating offshore wind turbine (FOWT) model in regular waves was carried out to clarify the floater elastic response and its influence on the floater motion. The model motion response from the experiment was compared with the numerical simulations by NK-UTWind and WAMIT codes. The dynamic elastic defo...
Article
Full-text available
A shallow draft cylindrical barge type floater with footing close to the water surface was experimentally evaluated in waves to investigate non-linear motion characteristics. The floater was designed to be used as an option for FOWT—floating offshore wind turbines. The non-linear mechanism can be promoted due to the viscous force that acts on the f...
Article
Full-text available
This study is focused on a maneuverability of a ship driven by POD propulsion systems which is widely used in cruise ships. Although the construction of these ships is not popular in Japan, many ships are coming to Japanese ports, which introduces the necessity to assess the maneuverability and fairway for the safety navigation. However, the maneuv...
Article
We have been developing an innovative water tank test system to improve the reliability of measurements, reduce design time, and develop high-performance hull forms. To develop such a test system, it is necessary to determine the accuracy of tank tests. Thus, we conducted an uncertainty assessment on the basis of repeated tests in the experimental...
Conference Paper
Full-text available
In this paper, we conducted the mathematical model for maneuvering ship motion of twin POD propulsion ships, based on captive model tests, following to the concept of MMG model and simple mathematical model of maneuvering motion of a two-propeller ships. In this construction, since the same mathematical model as the conventional propeller / rudder...
Article
Full-text available
Dead ships in rough sea make strong drifting motions and sometimes cause the significant accidents such as grounding or destroying offshore structures. For the prediction of such drift motion, it is necessary that the suitable mathematical model should be provided. Although many mathematical models for the conventional maneuvering ship motion are p...
Article
Full-text available
In order to reduce the CO2 emission from ships, International Maritime Organization executes the restriction of Energy Efficiency Design Index (EEDI) which limits amount of CO2 when freight of one ton is carried at one mile. Although the realization of higher efficiency of main engine without reduction of engine output is the best solution, it migh...
Conference Paper
Full-text available
Hydrodynamic forces in the streamwise and the transverse directions were measured in a towing tank on stationary and half-submerged cylinders with low aspect ratio aiming at understanding the free-surface effects. Since the Froude number mainly characterizes the movement of the free-surface, different circular cylinders with different diameters wer...
Book
Full-text available
This textbook is made by translating the textbook written in Japanese in 2012 into English to describe ship maneuvering motions. The knowledge on the ship maneuvering is indispensable for ship operators and ship designers. The ship maneuverability basically means the performance of motion response to rudder and/or propeller operation of a ship in c...
Conference Paper
In this study, model tests similar to Yoshimura's PCC are performed with bulk carriers. Based on the results, we propose a hull force model. In the proposed model, the yaw rate angle is used as a new parameter. This is introduced as an alternative to r' in order to prevent r' where this becomes infinite at U = 0. As an application example of this m...
Conference Paper
Full-text available
In this study, we conducted drifting experiments and compared them with the simulation results. The hydrodynamic forces were separately quantified according to the mathematical model in Reference 3) by conducting captive model tests with large oblique angle and turning.
Article
In this study, a practical maneuvering simulation method is presented considering the roll-coupling effect by extending an ordinal simulation model (3D-MMG model) proposed by Yasukawa and Yoshimura (J Mar Sci Technol 20:37–52, 2015), and adding the motion equation of roll. The roll moment acting on the hull is estimated by multiplying the hull late...
Article
Full-text available
A roll response model during maneuvering, which can express a transient motion after steering, is proposed. The transient motion, namely the transition process from initial inward heel to outward heel, is used in the rudder–roll stabilization system. Nowadays, the model reference control is well used as an autopilot system of the actual ship. As to...
Conference Paper
Full-text available
Japan team could get a gold medal at the female pursuit skating in Pyeongchang Olympics. There may be a fact that the air resistance is reduced by forming an in-line as the team compared with an individual single skating on the back ground. In order to confirm this phenomenon, we measure the fluid dynamic forth acting on three cylinders and conside...
Conference Paper
In this paper, we discuss the maneuverability of a ship sailing in a steady heel angle. First, we propose a simple maneuvering simulation model for a ship sailing in a heeled condition. In order to confirm its validity, a free-running model test of the turning performance of a car carrier sailing in a heeled condition is carried out, and the result...
Conference Paper
In this paper, we will conduct a model experiment to clarify the maneuvering hydrodynamic force when steering is performed with the ship speed decreasing and the oblique angle increasing, and at the same time, a mathematical model will be examined.
Conference Paper
Full-text available
In order to reduce the pitching of ship, an anti-pitching fin installed in bow had been proposed as one of the solutions1). Although there are many problems in the strength at a rough sea with heavy slamming condition, it has been reported by many researches2)~3) that the anti-pitching fin can successfully reduce the pitching. Further reduction of...
Conference Paper
Full-text available
Air lubrication has been put into practical use as a method of reducing hull resistance. However, in order to achieve this, a powerful blower that sends air bubbles to the bottom of the ship is indispensable. Therefore, in order to reduce the actual horsepower, it is necessary to subtract the energy of the blower from the energy reduction by air lu...
Conference Paper
Full-text available
It is not easy to control the pitching of a ship, but one method is anti-pitching fins. Although this fin has a problem in strength against wave load, it is possible to reduce pitching, and if this is further actively controlled, a further reduction effect is expected. On the other hand, wave propulsion, in which a large hydrofoil is attached to th...
Conference Paper
Full-text available
The design and construction history of Western sailing ships in Japan is poor, and since the beginning of the Meiji, Japanese people have tried to build them following the Western sailing ships. The sail training ships "Nippon-maru" and "Kaiwo-maru" in Japan were designed by England. Accordingly, Japan's new sail training ships were designed making...
Conference Paper
Full-text available
Twin-propeller and twin-rudder ships are widely used for from high-speed coastguard ships to low-speed wide beam cargo ships. One of the authors firstly proposed the simulation method for twin propeller and twin rudder ships by means of applying MMG mathematical model(2). After then, some experimental researches(3)~(4) were also published. However,...
Conference Paper
Full-text available
Phase 3, which is the final stage of IMO's EEDI regulation, requires that the index be reduced by 30% from the current level, and it is expected that the main engine output of vessels will be reduced. In connection with this, IMO is currently adopting the "provisional minimum output guideline" to maintain the maneuverability under stormy weather as...
Conference Paper
Full-text available
In this report, if the output of the main engine can be reduced without reducing the speed of the ship by some kind of improvement of the hull form or propulsion device, a general consideration will be given to the effect on the overall maneuvering performance of the ship.
Article
Full-text available
Twin-propeller ships are widely used for from high-speed coastguard ships to low-speed wide beam cargo ships. One of the authors¹⁾ firstly proposed the simulation method for twin propeller and twin rudder ships by means of applying MMG’s mathematical model. After then, some experimental researches2)~4) have been done. However, the manoeuvring predi...
Article
Full-text available
Ship manoeuvrability has been generally predicted based on 3-DOF mathematical model. However, medium-high speed ships such as containerships and passenger ferries make sometimes a large roll motion by the steering, which more or less affects on the ship manoeuvrability. Although a lot of researches have been done about the effect of roll motion, th...
Conference Paper
Full-text available
To establish a low carbon society, reduction of CO 2 emission from fossil fuels is vital. Therefore, developments of technologies for this purpose have become an important global issue. To fulfil the requirement in marine transportation, international protocols EEOI (Energy Efficiency Operational Indicator) and EEDI (Energy Efficiency Design Index)...
Article
Full-text available
Twin-propeller and Single-rudder Ships are frequently used for medium high-speed ships such as container ships and passenger ferry. However, the manoeuvring simulation for these ships is not easy because the interaction forces between propellers and rudder become very much complicated.In this paper, the authors have investigated a simple analysis a...
Article
Full-text available
In case of performing a free-running model test, a large scale ship model is generally required because of installing a lot of driving and measuring apparatus including power resources. When a large ship model is used, the production cost of ship model becomes higher and also a large basin is required. Therefore it becomes too expensive to carry ou...
Conference Paper
Full-text available
In this report, we will review successive sail equipped merchant ships and report the results of specific studies on the sailing effect when applied to EEDI, using the Wind Challenger 84 bulk carrier as an example.
Conference Paper
Full-text available
In this report, we examine mathematical models of propeller thrust / torque and rudder normal force during following wave/ oblique following wave. The model is based on the MMG model in calm water, and in order to confirm whether it is appropriate with the model of adding the wave orbital velocity to this, the propeller thrust in the restraint mode...
Conference Paper
Full-text available
In this paper, we add a restraint model experiment during following wave and oblique following wave conditions with the roll fixed, and confirm the effect of the difference in roll fixation and freedom on the hydrodynamic force. In addition, we pointed out the frequency effect on the wave exciting force in the left-right direction, but also in this...
Conference Paper
Full-text available
In response to the soaring oil prices caused by the oil crisis in the 1980s, many attempts to utilize renewable energy were examined. Among them, the development and design of wind power vessels that use wind energy have been actively carried out. These projects have declined as oil prices have fallen, but recently, as shown in IMO's EEDI and EEOI,...
Conference Paper
Full-text available
When medium‐speed ships are navigated, the ships can list in the roll direction by the turning motion. Additionally the roll motion can cause larger turning motion. This phenomenon has a potential risk of a boating disaster. Though the various studies about ship manoeuvrability with roll motion had been investigated, the many experiments to confirm...
Conference Paper
Full-text available
Today, it is important to reduce CO2 emissions, and it is necessary to develop energy-saving ships for ships. Sailing ships that use wind power, which is a natural energy source, are receiving renewed attention. It has been confirmed that sailing has the effect of reducing rolling in addition to obtaining propulsive force, which may have advantages...
Conference Paper
Full-text available
This report describes the results of a free-running model test using four types of model ships in order to investigate how the maneuvering performance is affected by the heel angle for various ship type. In addition, a 4DOF simulation including heel angle are performed, and while comparing these results with the above experimental results, the rela...
Conference Paper
Full-text available
The purpose of this report is to experimentally obtain the wave exciting force on hull in order to get the broaching simulation. Therefore, a model experiment was conducted using the fishing boat type as a test boat. In a large square water tank, the model ship was restrained by train during the follow-up and oblique follow-up waves, towed while ch...
Conference Paper
Full-text available
In case of performing a free-running model test, a large scale of ship model and basin are conventionally required because of the need of installing a lot of driving and measuring apparatus. They generally need the large cost for the model test. Therefore, it would be better and convenient if a small free-running ship model could be realized. The a...
Conference Paper
Full-text available
Developing control and measurement systems on a small ship model ship, more accurate experiments and clarification of the mechanism of surfing and broaching are done. In addition, a free-running test during following wave was conducted using a total station. The position of the model ship was successfully measured, and from the result, the change i...
Conference Paper
Full-text available
In this study, KCS container ship model was used as a test ship, and a simulation was performed by changing the expression of the hull force mathematical model when heel angle was added. Simulated results are also compared with the free-running model test results. Then the authors propose a practical and simple mathematical model of hull force mode...
Conference Paper
Full-text available
In this study, the authors try to apply the mathematical model for a conventional single propeller and rudder ship to the twin propeller ship. In this case, propeller revolution speed of √2 times and a propeller diameter of 1 / √2 times, respectively. Through the numerical simulations about a twin propeller ferry model, this procedure is very effec...
Conference Paper
Full-text available
In this study, we investigated the effect of rolling on maneuvering performance using a KCS container ship, a twin propeller/ single rudder ferry, and 135GT type purse seine fishing boat as test vessels. First, we conducted a restraint model test with heel angle as a parameter, measured the hydrodynamic force, clarified the physical mechanism of ma...
Conference Paper
Full-text available
From the viewpoint of energy saving and reduction of CO2 emissions, the use of renewable energy is an urgent task for ships. In this study, the estimation accuracy was examined from both CFD and experiments for the hard wing sails of the Wind Challenger Project (WCP), which aimed to take in a large amount of wind energy. The force of the sail equip...
Conference Paper
Full-text available
The authors developed a additional bottom plate on the stern bottom to prevent capsizing of fishing boats. In this paper, we examined the capsizing prevention effect of the plate on the stability. As a result, the capsizing prevention effect of the plate could be confirmed by the stability calculation, and the difference in the effect depending on...
Article
Full-text available
A lot of simulation methods based on Maneuvering Modeling Group (MMG) model for ship maneuvering have been presented. Many simulation methods sometimes harm the adaptability of hydrodynamic force data for the maneuvering simulations since one method may be not applicable to other method in general. To avoid this, basic part of the method should be...
Article
Roll-coupling effect on ship maneuvering motions is not negligible for high speed vessels, large container ships, passenger ships etc. To perceive the roll-coupling effect on the ship maneuverability, this paper proposes new simplified formulae for course stability criterion and steady turning index in the framework of the linear motion theory. The...
Conference Paper
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Conference Paper
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Conference Paper
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This study uses a 84BC which was planned for the purpose of taking in a large amount of wind energy. As a result, the change in rolling characteristics when sailing on a ship will be clarified by a water tank experiment. In addition, on sailing vessels, it was shown by experiments and theoretical analysis that rolling can be significantly reduced b...
Conference Paper
Full-text available
In this report, the hydrodynamic force with lateral inclination is measured in detail by the restraint model test, and a practical mathematical model is examined based on this result. In addition, a free-running model test was conducted on the same model ship, and the 4DOF simulation proposed in this report. We examine the validity of mathematical...
Conference Paper
Full-text available
In order to conduct more accurate experiments and clarify the mechanism of surfing and broaching, we have developed a maneuvering and measuring device that can be mounted on a small model ship. In addition, a free-running test during follow-up was conducted using a total station. The position of the model ship was measured, and from the result, the...
Conference Paper
Full-text available
For the purpose of preventing capsizing of fishing boats, an additive is installed on the bottom of the stern to try to prevent the loss of stability during waves. This appendage is characterized by having a density comparable to that of seawater and not affecting draft and trim. In this study, we created an appendage model with a simple shape, con...
Conference Paper
Full-text available
In this study, we focused on the change in GM during the follow-up in wave and still water. By replacing the GM with an experiment in which the GM was changed, the effect of lateral inclination on the maneuvering performance was clarified, and an attempt was made to examine the maneuvering performance during broaching. First, a free-running model t...
Conference Paper
Full-text available
In this study, we targeted fishing boats moored on the quay, and used a model boat assuming a 19-ton fixed net fishing boat to determine the mooring tension by experiments and moored while moored on the quay. A tension response model is theoretically introduced to clarify the mechanism by which mooring fracture occurs. Furthermore, using the theore...
Conference Paper
Full-text available
Manoeuvring prediction is indispensable for the ship designing stage. It becomes a serious concern that the manoeuvring performance complies with the IMO standard. For medium high-speed merchant ships such as container ship and PCC, they have the tendency that the advance and tactical diameter are estimated larger because of the too stable course-k...
Article
Full-text available
Ship's rudder is normally fuliy immersed under the stem. However, the rudder is partially exposed on the water surface in ballast conditions. The manoeuvring prediction in ballast conditions conventionally does not take account of such rudder expose to the water surface. There has been also little research on rudder force in such condition. In this...
Article
Full-text available
There are many serious accidents such as aground or ship's broken that is caused by the anchor dragging and often bring many loss of crew when ships are anchoring in a heavy storm. The captain has to decide whether the anchoring is suitable or not in such condition. For this purpose, it is required for him to predict the maximum mooring force prope...
Article
Full-text available
Nowadays, various CFD (Computational Fluid Dynamics) methods are used for simulating the flow around rudder or each appe ndage on the h ull. However, turbulent flow in 1 arge Reynolds number cannot be ca lculated easily by numerical method. Then, the turbulent flow models are introduced into the conventional CFD code. DNS (Direct Numerical Simulati...
Article
Full-text available
Japanese purse seiners often capsize and many crews lost their lives. Previous investigations or reports show that the cause of capsizing is surf-riding and broaching in following sea or wild operations or some mistakes of handling. In June 2008, however, the purse seiner capsized and sank when it was only drifting with sea anchor. As long as this...
Article
Full-text available
Reduction of ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargo as well as improving the comfort of the ride. It is a common experience for mariners, to see that steering with a rudder generally induces rolling of the ship, though the original aim of the rudder i...
Article
Full-text available
The authors have made the database of manoeuvring hydrodynamic coefficients for medium speed merchant ship and fishing vessels with one propeller and one rudder system. Then, the regression models which properly presume hydrodynamic coefficients are introduced based on this database. The concluding remarks are summarized below. 1. The linear hyd...
Article
Full-text available
Many researches have been done about the effect of a steering motion on roll motion, as the turning motion sometimes introduces a capsizing of ship and makes serious disasters. On the contrary, the researches of the effect of a roll motion on the manoeuvrability are very few, and the mechanism is not clear. In 1970s after the construction of a high...
Conference Paper
Full-text available
As for the center of buoyancy due to hydro-static pressure is assumed to be the geometric center of the immersed body. However, in many well-known ship arithmetic textbooks, there is almost no explanation as well as proof that the center of buoyancy is in the geometric center of the immersed body, and it looks like a scripture. For students startin...
Conference Paper
Full-text available
Large sail training ship Nippon-maru and Kaiwo-maru went into service 25 years ago. During the continuing voyage and training of young men who aim to become navigators and captains of foreign and domestic merchant ships. The sailing performance of the ship began with an estimation from aquarium and wind tunnel tests conducted one after another befo...
Conference Paper
Full-text available
This study focuses on the structure of large and medium-sized purse seine fishing boats in Japan, and examines the accident situation of the "58th Suwa Maru" whose cause has not yet been identified, and the purse seine vessels receive waves from various directions. The mechanism leading to capsizing was examined.
Conference Paper
Full-text available
In this report, in order to clarify the basic characteristics of the fluid force and steering response when accompanied by lateral tilt, the fluid force is linearized and a response model of turning motion to steering is introduced, and the effect of lateral tilt on steering performance is introduced. It was decided to obtain it analytically.
Conference Paper
Full-text available
More than 25 years have passed since the Nippon-maru and Kaiwo-maru went into service. .. We will introduce the sailing performance of large sailing vessels, starting with estimation from aquarium and wind tunnel tests conducted one after another before and after construction, to analysis of actual vessel operation results for 25 years.
Article
Full-text available
This paper describes the results of experimental and simulation studies that aimed at developing effective control methods for single-CPP single-rudder ships during the coasting manoeuvre and the stopping manoeuvre. In order to improve the manoeuvrability of CPP ships under coasting, the authors performed full-scale experiments and confirmed that C...
Article
Full-text available
This paper addresses the dynamics model of an underwater vehicle with a water-jet propulsion system. Our aim is to develop the vehicle for the use of oceanographic survey, fisheries and ocean exploration. Hydrodynamic forces acting on the vehicle with 4 fins are determined for -90.0〜90.0 degrees of attack angle and -2.0〜2.0 of non-dimensional rate...
Article
Circular motion test data and uncertainty analysis results of investigations of the hydrodynamic characteristics of ship maneuvering are presented. The model ships used were a container ship and two tankers, and the measured items were the surge and sway forces, yaw moment, propeller thrust, rudder normal and tangential forces, pitch and roll angle...
Article
Full-text available
When a ship is anchoring in a stormy weather, the anchor often comes off due to the extreme overload of the mooring force. Then, the ship begins to run and sometimes causes aground, and this makes a serious disaster. The accident of "Toya-maru" was also one of them. There are still such accidents and lost many crew in these days. However, the mecha...
Article
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When a ship is proceeding into the shallow water, ship's sinkage and bow trim are increased. These tendencies become larger as the bottom clearance is decreased. This phenomenon is generally called as squat, and this sometimes makes the bottom touch or aground in harbour or fairway, and then caused the serious marine disaster such as oil prolusions...