Numerical simulations of underwater vehicle wake flow field and propeller excitation force were performed to evaluate the performance of the k-ω SST RANS and k-ω IDDES turbulence models. First, the nominal wake of the SUBOFF model and open water characteristics of the INSEAN E1619 propeller were compared to the experimental measurements to validate the numerical method. Then, the flow field around

Deterministic sea wave prediction (DSWP) provides an effective way of predicting time history for a fixed point or spatial wave elevation on a fixed snapshot. DSWP models are realized by assimilating various phase-resolved wave models and measured wave data. For a given prediction accuracy level, the predictable zone is affected by the distance between the measurement and forecasting locations, the

This note focuses on the leader–follower formation control problem of underactuated surface vehicles (USVs) with the unknown environmental disturbance. Especially, due to the ocean environmental disturbance, the vehicle’s desired-heading angle is altered violently. To address the constraint, a reduced-order extended state observer (ESO) is introduced. The sideslip angle of the vehicle is estimated

The propulsion shafting is one of the main excitation sources of ship vibration and noise. Thus, shafting vibration and alignment are very important issues in the design of a propulsion system. In the present paper, the effects of shafting alignment on shafting whirling and bearing vibrations will be discussed. This study has been carried out experimentally on a test rig designed by the Wuhan University

Using the stochastic averaging method, the probability density function (PDF) of roll motion for parametric rolling in irregular waves is obtained. In this paper, the stochastic averaging method using Hamiltonian proposed by Dostal is used, and the PDF of roll amplitude and Hamiltonian are derived from the equations of roll motion. In addition, the asymptotic behavior of PDF is investigated to improve

In this research, a camber changing mechanism feasible for use in a flapping hydrofoil tidal stream turbine is suggested to generate high lift force and subsequently a large flapping angle as a dynamic response. The hydrodynamic characteristics of rigid and variable-camber hydrofoils, which mainly affect the response, were numerically obtained using XFOIL. The flapping responses of the hydrofoils were

Trajectory planning is one of the important technologies to ensure the safe navigation of the unmanned ship. This paper presents a dynamic path planning method based on the multi-layer Morphin adaptive search tree algorithm, which considers ship maneuverability, COLREGS, and good seamanship to harmonize the actions in the mixed traffic environment. First, the environment model is built according to

The time derivative of acceleration is called a jerk, which is an important property to evaluate ride comfort in elevators, cars, and so on. Likewise, evaluation of motion sickness or ride comfort on a vessel could be achieved by this jerk property in the future. In this paper, we utilize the PDF Line Integral Method (PLIM), which was newly contrived in our previous research, for calculating not only

This paper proposes a novel system identification scheme to obtain a MIMO model of ship maneuvering motion, which can leverage the temporal correlation from the constructed training data to learn the underlying feasible model robust to extraneous noise. The scheme is based on long–short-term-memory (LSTM) deep neural network, which is more easily trained than traditional feedforward neural network

A correction to this paper has been published: https://doi.org/10.1007/s00773-021-00821-1

When waves from two weather systems converge at a certain sea area, cross waves can be produced. It is important to have a better understanding of the motion characteristics of ship in cross sea to ensure its navigation safety. In this paper, the motion responses of a S175 container ship hull in cross sea is first analyzed based on CFD technique using RANS method. VOF method is used to model and capture

Current guidelines for approval of autonomous ship systems are focused on the ships’ concrete operations and their geographic area. This is a natural consequence of the link between geography and the navigational complexity, but moving the ship to a new area or changing owners may require a costly re-approval. The automotive industry has introduced the Operational Design Domain (ODD) that can be used

With the development of deep-sea oil and gas resources, the aspect ratio of deep-sea flexible riser has reached the order of 102–103, which makes the experimental model of the equal scale of deep-sea flexible risers challenging to achieve under typical experimental conditions. Alternatively, the non-scale experiment is sometimes used. However, the dynamic response of the prototype may not be exactly

There are typically unknown deviation tides and stochastic measurement errors in digital elevation map and real-time measurement terrain map, which result in the failure of the matching algorithm. To address the problem of the robust terrain-aided position under the condition of unknown tidal and measurement errors, a new terrain-aided position (TAP) model and a tide level estimation method based on

A methodology for predicting the probability density function of roll motion for irregular beam seas is developed in the author’s previous research. In this paper, two methods for the prediction of the probability density function (PDF) of the rolling amplitude are examined. One of these methods is an approach based on a non-Gaussian PDF with the use of the equivalent linearization and the moment method

The coupled motion of roll and pitch is noticeable when trimaran sails in oblique head waves, which will lead to negative influence on the safety and comfort of navigation. In this paper, the numerical simulation of the trimaran's motion in oblique waves was carried out by open source CFD tool OpenFOAM, and the computed motion response was analyzed to study the characteristics of the torsional rolling

Thrust allocation is of great importance for the application of Dynamic Positioning System (DPS). For dynamically positioned vessels, the thrust allocation is formulated as a nonlinear optimization problem, where the demanded forces and moments are distributed among the available thrusters. Both hydrodynamic interaction effects and physical limitations of thrusters affect the thrust generation. Therefore

This paper proposes a hybrid robust-adaptive learning-based control scheme based on Approximate Dynamic Programming (ADP) for the tracking control of autonomous ship maneuvering. We adopt a Time-Delay Control (TDC) approach, which is known as a simple, practical, model free and roughly robust strategy, combined with an Actor-Critic Approximate Dynamic Programming (ACADP) algorithm as an adaptive part

The development of an offshore deepwater oilfield is a complex and risky task. One core problem in this project is the selection of a production system that maximizes oil recovery and minimizes investment and operational costs while meeting external, economic, environmental, societal and technological demands under a scenario of uncertainties. Although several studies address this problem in the literature

The result from a multi-objective optimization on the outlet diffuser angle of the tidal turbine is presented with a focus on the turbine efficiency and cavitation. This study is the first to investigate the impact of the diffuser angle on the diffuser augmented tidal turbine in performance and cavitation inception. The 1/2 scale model was designed with three blades based on NACA 4616 airfoil. Seven

Understanding the complex flow fields behind the propeller and the structure of vortex shedding of cycloidal propellers are essential to analyzing the instantaneous forces on the blades and the overall hydrodynamic performance. In this paper, numerical simulation is performed to investigate the hydrodynamics and vortex shedding of cycloidal blades. The numerical results agree well with experimental

A correction to this paper has been published: https://doi.org/10.1007/s00773-021-00806-0

Trends of large-scale ships have seen propulsion shaft and propeller sizes increase. This has enabled shafts to have greater stiffness, yet has caused flexibility to lessen and induce bearing failure at the aft stern tube bearing. In general, shaft alignment is calculated and evaluated in accordance with classification societies’ rule requirements. Especially, positioning reaction support and stiffness

A correction to this paper has been published: https://doi.org/10.1007/s00773-021-00807-z

A novel numerical method combining Eigenfunction matching method (EMM) and 3D Rankine source method is developed to investigate wave-body interaction over a sloping bottom. The extended EMM is proposed to create an incident wave model over the sloping bottom, thereby obtaining the Froude-Krylov force and Neumann data on wet surfaces of the floating body for the diffraction problem. A 3D Rankine source

To minimize the energy consumption of contra-rotating propellers (CRPs), the optimal matched rotational speeds of the forward propeller (FP) and rear propeller (RP) of CRP are investigated based on the potential-based panel method. The optimal matching problem of a set of CRP405 is investigated. The open-water hydrodynamic performances of CRP405 with the FP and RP having the same rotational speed are

Finite Element Method (FEM) and Smoothed Particle Hydrodynamics (SPH) method are effective methods to study the interaction between marine structures and sea ice. However, both FEM and SPH methods have their own shortcomings in numerical simulations. There are mesh distortions and disappearance in FEM, and tensile instability, difficulty in applying boundary conditions, and low computational efficiency

This paper presents the flow-induced forces over 3-column arrays with different cross-sectional geometries due to the current incidence only, using Computational Fluid Dynamics (CFD) calculations for a low Reynolds number (\(\mathrm{Re}\)). The flow around circular, square, and diamond sections of 3-column arrays was evaluated for stationary conditions (i.e., with no degrees of freedom). These analyses

A numerical model considering the seabed friction is developed to investigate the dynamic behavior of anchor cable in this paper. In the model, the anchor cable was divided into hanging and lying parts. The governing equations of hanging and lying anchor cables were established respectively based on finite difference method and coupled according to the boundary conditions. The coupled equations of

Fuel consumption is an important factor to be considered in the process of weather routing. How to choose an appropriate route according to the requirements is particularly important. This paper proposes a method to optimize the ship weather routing. Based on the original genetic algorithm, the trigonometric function selection operator is introduced, the mutation operator is improved to increase the

Wind propulsion for commercial ships has been identified as a key component in the energy transition for the maritime industry. The sailing hybrid ship will operate with leeway (drift) angles to produce a lateral force known as sideforce, for steady operation under sail. In this paper, experimental results for the sailing performance of ships fitted with bilge keel appendages are presented. Systematic

Since large heave and pitch motions of a high-speed multihull seriously affect the navigability of the ship, it is significant to design the effective anti-pitching control for the multihull. However, the existing anti-pitching controllers are all designed based on deterministic dynamics models and have disadvantages of low control robustness, high dependence on experience, high complexity and low

Artificial intelligence is an enabling technology for autonomous surface vehicles, with methods such as evolutionary algorithms, artificial potential fields, fast marching methods, and many others becoming increasingly popular for solving problems such as path planning and collision avoidance. However, there currently is no unified way to evaluate the performance of different algorithms, for example

In this study, a six degrees of freedom (6-DOF) motion simulation method of a ship steering in regular waves is validated. The proposed simulation model is based on the two-time scale concept where the 6-DOF motions are expressed as the sum of the low-frequency maneuvering motions and high-frequency wave-induced motions. Turning simulations of a KCS container ship model with a rudder angle of \(\pm

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 \(\beta \) in the range of \(-180^{\circ } \sim 180^{\circ }\), which encompasses

Autonomous surface vehicles are gaining increasing attention worldwide due to the potential benefits of improving safety and efficiency. This has raised the interest in developing methods for path planning that can reduce the risk of collisions, groundings, and stranding accidents at sea, as well as costs and time expenditure. In this paper, we review guidance, and more specifically, path planning

When the ship speed exceeds a certain level in shallow water, ship-bank interaction induces great influence on the ship’s manoeurability with some special hydrodynamic characteristics, but the mechanism is not totally understood. This paper presents a numerical prediction of the ship-bank interaction for the model of the KRISO Container Ship. An unsteady Reynold-Averaged Navier Stokes solver is applied

In the presence of unknown environmental disturbances, this paper develops a robust adaptive synchronization navigation control design with prescribed performance for the supply ship during underway replenishment using the adaptive technique, the prescribed performance control (PPC) technique and the command-filtered backstepping approach. The adaptive law is derived to estimate the bounds of unknown

Shallow-water sloshing motions in a three-dimensional rectangular tank are investigated. The Boussinesq-type equations in terms of velocity potential and the finite-difference scheme are applied for the solutions of numerical model. Through linking the rate of decay of the wave amplitudes to the energy dissipation due to the friction at the tank walls, a linear damping term is proposed and added into

Collision avoidance path planning is still one of the essential problems in the design and application of an intelligent maritime navigation system. Its main obstacle is how to determine effective and cooperative collision avoidance maneuvers within a multi-ship encounter situation. By deconstructing a multi-ship encounter, this study adopted ship domain around target ships to assess the collision

This paper presents a procedure for the estimation of propeller effective wakes in oblique flows. It shows how a recently developed method for controlling coupling errors can be applied to analyze propellers operating in off-design conditions. The approach allows the use of fast potential flow methods for the representation of the propeller in the context of viscous flow solvers and works accurately

A numerical method for solving 3D unsteady potential flow problem of ship advancing in waves is put forward. The flow field is divided into an inner and an outer domain by introducing an artificial matching surface. The inner domain is surrounded by ship wetted surface and matching surface as well as part of the free surface. The free surface condition for the inner domain is formulated by perturbation

This paper presents a method for preliminary design of the control which is needed to achieve underwater vehicle trajectories. The proposed way allows one to evaluate dynamics of underwater vehicle using a trajectory tracking control algorithm. At the first stage, we propose the controller, and at the second, we test dynamics of the system based on the properties resulting from the transformed equations

In this paper, the application of artificial neural network in ship course control systems is investigated. Two-multilayered feed-forward neural network course control system is proposed. The first neural network plays the role of ship forward dynamic approximator. The second one is the course controller. Both neural networks are trained in a quasi-online regime using training data acquired from system

Multiple pipes bundled with a certain distance are used for deep ocean development for such as lifting seafloor massive sulfides (SMS), pumping up a large amount of cooling water for onboard natural gas liquefaction, and production of oil/gas. To understand the vortex-induced phenomenon of fluids and the structural mutual interference among pipes in a steady flow, a towing tank test using a model of

In recent years, the size of container ships has become larger, thus requiring a more evident assurance of the hull structural safety. In order to evaluate the structural safety in operation, it is necessary to grasp the encountered sea state. The aim of this study is to estimate the encountered sea state using machine learning from measurement data of ocean-going 14,000TEU container ships. In this

Ship–seabed interaction is highly critical to ship safety and ship performance when ship operates over shallow water with uneven seabed. However, the prediction method for ship reaction is still yet to be fully developed. In this paper, a high-fidelity transient numerical simulation method with sliding mesh is developed based on computational fluid dynamics to model a vessel passing a step bank, demonstrating

To resolve the severe wear problems of steering engine and fin stabilizer, the nonlinear response characteristics of steering engine and fin stabilizer are studied by analyzing sea trial data of ship Yukun. The nonlinear response characteristics are summarized and applied to a rudder and fin hybrid control system. Decoupling, \(\hbox {H}_\infty\) and \({\rm H}_2\) controllers are designed to achieve

To ensure that the unmanned underwater vehicles (UUVs) can still successfully complete the corresponding tasks in the case of thrusters having faults, a novel fault-tolerant control strategy which combines the model predictive control (MPC) algorithm and the fault-tolerant reconstruction algorithm is presented in this paper. Firstly, a cascade control method based on model predictive control algorithm

Recently, the great enlargement of container ships has brought broad concern on the effect of whipping response. Meanwhile, the accompanying wider width of double bottom may cause more flexible responses of the double bottom structures. The numerical simulation studies have shown that the longitudinal stresses of the hold central bottom of a container ship due to the double bottom bending superimpose

How to calculate the 3D time-domain Green function and its gradients accurately and efficiently is the key to solving the hydrodynamic problem of ships. In this paper, the least square support vector machine (LS-SVM) theory was proposed for the first time to solve the ordinary differential equations (ODEs) satisfied by the time-domain Green function and the spatial derivatives in time domain. Furthermore

Propeller is the main device in marine vehicle to generate propulsive energy. During practical manoeuvring condition, it losses a major part of energy due to the formation of hub as well as tip vortex. This fact becomes a great concern for researcher and motivates to find some alternate energy saving device (ESD). In this paper numerical investigations, based on Reynolds Average Navier Stokes (RANS)

Currently, accelerated research on automation is involved in most fields associated with vehicle manufacturing. In the area of autonomous operation of marine vehicles, automatic berthing remains a problem due to the nonlinearity of the low-speed maneuvering model, poor control of the vessel at low speed, and collision with berth danger. A previous study on off-line automatic berthing reveals frequent

The prevention of excessive roll acceleration is one of the fundamental requirements of an oceangoing vessel at sea. In this paper, aiming at this requirement, we propose a new theoretical method for calculating roll angular acceleration, called “PDF line integral method.”. This paper presents the derivation of this method and a numerical comparison with Monte Carlo simulation (MCS) results; also,

Shipyard hoisting process is a project type manufacturing process which entails more sophisticated elements and relationships than other kinds of processes, this feature brings particular challenges when constructing a structured description of the process, called enterprise model, to introduce various Computer Integrated Manufacturing (CIM) technologies. However, most of the modelling methods devised

The Marine Environmental Committee (MEC) ocean model was applied to Onagawa Bay to examine the bay-scale water circulation and to evaluate the current configuration of aquaculture facilities that were devastated by the 2011 Tohoku earthquake. In this study, the drag forces of aquaculture facilities and the blocking effects of both stocked fish and shellfish were integrated to MEC ocean model. The model

Predicting the wave-induced response in the near-future is of importance to ensure safety of ships. To achieve this target, a possible method for deterministic and conditional prediction of future responses utilizing measured data from the most recent past has been developed. Herein, accurate derivation of the autocorrelation function (ACF) is required. In this study, a new approach for deriving ACFs

In this study, different operation factors affecting a ship’s wave statistics are studied, such as the slow steaming and voyage optimizations. Especially, the impact of various voyage optimization methods on the long-term wave statistics and corresponding fatigue damage during ship operations is investigated by comparing the encountered waves with the design wave scatter diagram. Three years of full-scale

The accuracy of underwater acoustic positioning is greatly influenced by both systematic error and gross error. Aiming at these problems, the paper proposes a robust zero-difference Kalman filter based on the random walk model and the equivalent gain matrix. The proposed algorithm takes systematic error as a random walk process, and estimates it together with the position parameters by using zero-difference

In the study of the cross-flow vortex-induced vibration of the cylinder, it is found that with the increase in the Reynolds number, the upper branch of the vibration amplitude and the lock-in region show an increasing trend. Currently, there are relatively few studies on two-degree-of-freedom VIV at high Reynolds number. In this paper, the Launder and Sharma low Reynolds number k–ɛ turbulence model