In a general case, container ship serves many different ports on each voyage. A stowage planning for container ship made at one port must take account of the influence on subsequent ports. So the complexity of stowage...In a general case, container ship serves many different ports on each voyage. A stowage planning for container ship made at one port must take account of the influence on subsequent ports. So the complexity of stowage planning problem increases due to its multi-ports nature. This problem is NP-hard problem. In order to reduce the computational complexity, the problem is decomposed into two sub-problems in this paper. First, container ship stowage problem (CSSP) is regarded as 'packing problem', ship-bays on the board of vessel are regarded as bins, the number of slots at each bay are taken as capacities of bins, and containers with different characteristics (homogeneous containers group) are treated as items packed. At this stage, there are two objective functions, one is to minimize the number of bays packed by containers and the other is to minimize the number of overstows. Secondly, containers assigned to each bays at first stage are allocate to special slot, the objective functions are to minimize the metacentric height, heel and overstows.The taboo search heuristics algorithm are used to solve the subproblem. The main focus of this paper is on the first subproblem. A case certifies the feasibility of the model and algorithm.展开更多
This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/...This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/2 000 kVA) for the quay cranes is used for the power input of the system, after frequency and voltage converting (450 V/60 Hz), then putting out and supplying to vessel. This system is flexible with positive effect on energy-saving and emission reduction; besides, there's no requirement of civil reconstruction to container terminals, which is suitable for the busy ports in China.展开更多
In order to reduce waiting time in port for large LNG （liquefied natural gas） fueled ships, it is suggested that LNG STS （ship to ship） bunkering and cargo loading/unloading should be carried out simultaneously. T...In order to reduce waiting time in port for large LNG （liquefied natural gas） fueled ships, it is suggested that LNG STS （ship to ship） bunkering and cargo loading/unloading should be carried out simultaneously. This study investigated the safety zone of an LNG bunkering vessel with 10,000 cubic meters capacity transferring LNG fuel to an LNG fueled 18,000 TEU containership. Four LNG leakage scenarios were identified based on failure frequencies analysis of piping systems and severity of consequence, three-dimension CFD software FLACS was adopted to calculate flammable cloud dispersion after LNG leakage. As a result, we obtained a rectangle dangerous zone （41.3 m ~ 126 m）, outside of this dangerous zone can be def＇med as safety zone. It is concluded that safety zone of LNG STS bunkering and cargo loading/unloading SIMOPS （simultaneous operations） cannot keep the same, there are different results for different designs and operation locations. Due to high frequencies and severe consequences, two typical scenarios, the leakage of LNG hose and the natural gas releases from bunkering tank＇s safety relief valve during bunkering, cannot be ignored in similar study.展开更多
CIFER software is used to identify steering and roll dynamics of a container ship. In this software, advanced features such as the Chirp-Z transform(CZT) and composite window optimization are applied to the time histo...CIFER software is used to identify steering and roll dynamics of a container ship. In this software, advanced features such as the Chirp-Z transform(CZT) and composite window optimization are applied to the time history of steering and roll dynamics to extract high quality frequency responses. From the extracted frequency responses, two linear transfer functions of Nomoto model are fitted for yaw and roll dynamics of the vessel. Based on the identified Nomoto model, a PID heading controller and a Kalman filter observer are constructed. The simulation results of heading controller for line of sight(LOS) waypoint guidance show excellent tracking of pilot inputs in the presence of wave induced motions and forces.展开更多
This paper investigates mathematical modelling of response amplitude operator （RAO） or transfer function using the frequency-based analysis for uncoupled roll motion of a floating body under the influence of small a...This paper investigates mathematical modelling of response amplitude operator （RAO） or transfer function using the frequency-based analysis for uncoupled roll motion of a floating body under the influence of small amplitude regular waves. The hydrodynamic coefficients are computed using strip theory formulation by integrating over the length of the floating body. Considering sinusoidal wave with frequency （ω ） varying between 0.3 rad/s and 1.2 rad/s acts on beam to the floating body for zero forward speed, analytical expressions of RAO in frequency domain is obtained. Using the normalization procedure and frequency based analysis, group based classifications are obtained and accordingly governing equations are formulated for each case. After applying the fourth order Runge-Kutta method numerical solutions are obtained and relative importance of the hydrodynamic coefficients is analyzed. To illustrate the roll amplitude effects numerical experiments have been carried out for a Panamax container ship under the action of sinusoidal wave with a fixed wave height. The effect of viscous damping on RAO is evaluated and the model is validated using convergence, consistency and stability analysis. This modelling approach could be useful to model floating body dynamics for higher degrees of freedom and to validate the result.展开更多
Ships which have large structures above water surface,such as pure car carriers(PCCs) and container vessels,have large speed reduction by wind pressure.In the present study,the running speed of a large PCC with two or...Ships which have large structures above water surface,such as pure car carriers(PCCs) and container vessels,have large speed reduction by wind pressure.In the present study,the running speed of a large PCC with two or more sails for using wind power is simulated.The simulated results demonstrate that the ship can keep a constant service speed even in winds of 20m/s except head and bow winds.This sail system can shorten annual average navigation time by about 4 hours per voyage.展开更多
Container vessels navigate among the world＇s ports, frequently passing through narrow and congested waters. Due to the many layers of containers on a container vessel＇s decks, it is difficult for the crew to be awar...Container vessels navigate among the world＇s ports, frequently passing through narrow and congested waters. Due to the many layers of containers on a container vessel＇s decks, it is difficult for the crew to be aware of all fishing vessels and other obstacles in a container vessel＇s radar observation blind zone. This greatly increases the risk of collisions and other accidents. Given such great challenges to safe navigation and safety management with container vessels, their security risks are severe. An effective visual monitoring system can improve the safety of the water area surrounding container vessel by eliminating a vessel＇s observation blind zone, providing an effective safety measure for vessels navigating fishing zones and other troublesome areas. The system has other functions, such as accident recording, ship security, and monitoring of loading and unloading operations, thus ensuring the ship operates safely. Six months＇ trial operation showed that the system facilitates safe navigation of container vessels.展开更多
Reynold＇s averaged Navier-Stokes based CFD （computational fluid dynamics） technique WISDAM developed at The University of Tokyo is used to investigate and compare the hydrodynamic loads on container ship models SR1...Reynold＇s averaged Navier-Stokes based CFD （computational fluid dynamics） technique WISDAM developed at The University of Tokyo is used to investigate and compare the hydrodynamic loads on container ship models SR108 and KCS in 120 degree regular oblique wave conditions. WISDAM has the capability of handling 6DOF （six degrees of freedom） in ship motions. Finite volume method with structured and overlapping grid system is employed. The flow variables are described in staggered manner, i.e., velocity components arc defined at the face center while pressure is at the cell center. Computational results agree favorably well with existing towing tank results especially for ship motions. Computational results also show that ship with bulbous bow experience higher hydrodynamic loads on bow section.展开更多
The cost advantage of Arctic NEP （Northeast Passage） is mainly analyzed. The traditional southern route through the Suez Canal between the East Asia and the Europe is referred as benchmark routte, general cargo ship...The cost advantage of Arctic NEP （Northeast Passage） is mainly analyzed. The traditional southern route through the Suez Canal between the East Asia and the Europe is referred as benchmark routte, general cargo ship and container ship are respectively selected as benchmark ships, which are analyzed and compared with Arctic NEP from fuel consumption, insurance, icebreaker fees and cost for SOLAS amendment, etc. The study reveals that Arctic NEP highly reduces general cargo ships＇ sailing time, container ships＇ fuel consumption, and contributes to shipping＇s sustainable development.展开更多
基金Supported by a Special Fund Support Item of Doctor Subject of Colleges and Universities (No. 2000014125)
文摘In a general case, container ship serves many different ports on each voyage. A stowage planning for container ship made at one port must take account of the influence on subsequent ports. So the complexity of stowage planning problem increases due to its multi-ports nature. This problem is NP-hard problem. In order to reduce the computational complexity, the problem is decomposed into two sub-problems in this paper. First, container ship stowage problem (CSSP) is regarded as 'packing problem', ship-bays on the board of vessel are regarded as bins, the number of slots at each bay are taken as capacities of bins, and containers with different characteristics (homogeneous containers group) are treated as items packed. At this stage, there are two objective functions, one is to minimize the number of bays packed by containers and the other is to minimize the number of overstows. Secondly, containers assigned to each bays at first stage are allocate to special slot, the objective functions are to minimize the metacentric height, heel and overstows.The taboo search heuristics algorithm are used to solve the subproblem. The main focus of this paper is on the first subproblem. A case certifies the feasibility of the model and algorithm.
文摘This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/2 000 kVA) for the quay cranes is used for the power input of the system, after frequency and voltage converting (450 V/60 Hz), then putting out and supplying to vessel. This system is flexible with positive effect on energy-saving and emission reduction; besides, there's no requirement of civil reconstruction to container terminals, which is suitable for the busy ports in China.
文摘In order to reduce waiting time in port for large LNG （liquefied natural gas） fueled ships, it is suggested that LNG STS （ship to ship） bunkering and cargo loading/unloading should be carried out simultaneously. This study investigated the safety zone of an LNG bunkering vessel with 10,000 cubic meters capacity transferring LNG fuel to an LNG fueled 18,000 TEU containership. Four LNG leakage scenarios were identified based on failure frequencies analysis of piping systems and severity of consequence, three-dimension CFD software FLACS was adopted to calculate flammable cloud dispersion after LNG leakage. As a result, we obtained a rectangle dangerous zone （41.3 m ~ 126 m）, outside of this dangerous zone can be def＇med as safety zone. It is concluded that safety zone of LNG STS bunkering and cargo loading/unloading SIMOPS （simultaneous operations） cannot keep the same, there are different results for different designs and operation locations. Due to high frequencies and severe consequences, two typical scenarios, the leakage of LNG hose and the natural gas releases from bunkering tank＇s safety relief valve during bunkering, cannot be ignored in similar study.
文摘CIFER software is used to identify steering and roll dynamics of a container ship. In this software, advanced features such as the Chirp-Z transform(CZT) and composite window optimization are applied to the time history of steering and roll dynamics to extract high quality frequency responses. From the extracted frequency responses, two linear transfer functions of Nomoto model are fitted for yaw and roll dynamics of the vessel. Based on the identified Nomoto model, a PID heading controller and a Kalman filter observer are constructed. The simulation results of heading controller for line of sight(LOS) waypoint guidance show excellent tracking of pilot inputs in the presence of wave induced motions and forces.
基金The financial grant of Islamic Azad University Kermanshah branch,Iran(Grant No:35/3/622281,7-9-2009)
文摘This paper investigates mathematical modelling of response amplitude operator （RAO） or transfer function using the frequency-based analysis for uncoupled roll motion of a floating body under the influence of small amplitude regular waves. The hydrodynamic coefficients are computed using strip theory formulation by integrating over the length of the floating body. Considering sinusoidal wave with frequency （ω ） varying between 0.3 rad/s and 1.2 rad/s acts on beam to the floating body for zero forward speed, analytical expressions of RAO in frequency domain is obtained. Using the normalization procedure and frequency based analysis, group based classifications are obtained and accordingly governing equations are formulated for each case. After applying the fourth order Runge-Kutta method numerical solutions are obtained and relative importance of the hydrodynamic coefficients is analyzed. To illustrate the roll amplitude effects numerical experiments have been carried out for a Panamax container ship under the action of sinusoidal wave with a fixed wave height. The effect of viscous damping on RAO is evaluated and the model is validated using convergence, consistency and stability analysis. This modelling approach could be useful to model floating body dynamics for higher degrees of freedom and to validate the result.
文摘Ships which have large structures above water surface,such as pure car carriers(PCCs) and container vessels,have large speed reduction by wind pressure.In the present study,the running speed of a large PCC with two or more sails for using wind power is simulated.The simulated results demonstrate that the ship can keep a constant service speed even in winds of 20m/s except head and bow winds.This sail system can shorten annual average navigation time by about 4 hours per voyage.
基金the Shanghai Leading Academic Discipline Project Foundation under Grant No.T0603
文摘Container vessels navigate among the world＇s ports, frequently passing through narrow and congested waters. Due to the many layers of containers on a container vessel＇s decks, it is difficult for the crew to be aware of all fishing vessels and other obstacles in a container vessel＇s radar observation blind zone. This greatly increases the risk of collisions and other accidents. Given such great challenges to safe navigation and safety management with container vessels, their security risks are severe. An effective visual monitoring system can improve the safety of the water area surrounding container vessel by eliminating a vessel＇s observation blind zone, providing an effective safety measure for vessels navigating fishing zones and other troublesome areas. The system has other functions, such as accident recording, ship security, and monitoring of loading and unloading operations, thus ensuring the ship operates safely. Six months＇ trial operation showed that the system facilitates safe navigation of container vessels.
文摘Reynold＇s averaged Navier-Stokes based CFD （computational fluid dynamics） technique WISDAM developed at The University of Tokyo is used to investigate and compare the hydrodynamic loads on container ship models SR108 and KCS in 120 degree regular oblique wave conditions. WISDAM has the capability of handling 6DOF （six degrees of freedom） in ship motions. Finite volume method with structured and overlapping grid system is employed. The flow variables are described in staggered manner, i.e., velocity components arc defined at the face center while pressure is at the cell center. Computational results agree favorably well with existing towing tank results especially for ship motions. Computational results also show that ship with bulbous bow experience higher hydrodynamic loads on bow section.
文摘The cost advantage of Arctic NEP （Northeast Passage） is mainly analyzed. The traditional southern route through the Suez Canal between the East Asia and the Europe is referred as benchmark routte, general cargo ship and container ship are respectively selected as benchmark ships, which are analyzed and compared with Arctic NEP from fuel consumption, insurance, icebreaker fees and cost for SOLAS amendment, etc. The study reveals that Arctic NEP highly reduces general cargo ships＇ sailing time, container ships＇ fuel consumption, and contributes to shipping＇s sustainable development.
