bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Design by Optimisation Approach for Hybrid Propulsion Systems Sizing Using Actual Sailing Profiles
Authors: Vasilikis Nikolaos I. , Geertsma Rinze , Oneto Luca , Coraddu Andrea 
Published: August 2024

Abstract
Hybrid propulsion is considered a promising alternative to diesel mechanical propulsion which can assist the maritime industry to mitigate its contribution to climate change. The energy performance of new designs for most ship types is evaluated with the regulated Energy Efficiency Design Index (EEDI), though its limited consideration of one design point in calm water conditions and installed rated power is characterised as insufficient or even dangerous by many authors. Nevertheless, individual sailing conditions are expected to influence the resulting carbon footprint. The automotive and aviation industries have already adopted the energy assessment of new designs over operating cycles such as the Worldwide harmonized Light-duty vehicles Test Cycle (WLTC) or the Landing and Take-Off cycle (LTO). This paper demonstrates a new approach for the resizing of the hybrid propulsion system of an ocean patrol vessel of the Royal Netherlands Navy. It utilizes the actual sailing profile of a vessel based on logged high frequency operational-data. Carbon intensity is predicted by a state of the art digital twin of the vessel’s energy system developed by the authors in a previous stage. Results suggest that calm water conditions can potentially overestimate carbon intensity improvements and point to different optimal designs thus actual profiles must be used in future analyses.
Research on the Future Development of Lock Ship Type in the Three Gorges Main Line of Yangtze River
Authors: Xu Haoran , Wang Hao , Zhang Yanbing , Wang Lizheng 
Published: August 2024

Abstract
With the continuous development of the economy, the demand for waterway transportation is increasing, the Three Gorges locks as an important transportation hub on the Yangtze River, the problem of insufficient throughput capacity is highlighted, the development of the ship type to give full play to the capacity of the Three Gorges locks as well as the social benefits brought about by the Three Gorges locks has a very important significance. Based on the establishment of simulation model for ships passing through the Three Gorges locks, simulate the ship passing process, from the perspective of the ship’s own technology and economy and the main social benefits of the ship, combined with the adaptability of the lock facilities, the establishment of the main indexes of the demonstration, and the construction of the ship type demonstration of the comprehensive evaluation model, to comprehensively measure the comprehensive performance of the future ship type of the Yangtze River trunk line passing locks; in order to improve the passing capacity of the locks as one of the main objectives, put forward the future of the Three Gorges locks on the Yangtze River trunk line. With the main objective of improving the passing capacity of the locks, the future ship type scale of the Three Gorges mainline is proposed, as well as the representative ship type and lock chamber scale for the construction of the new Three Gorges corridor under different navigational conditions, and the results of the demonstration will provide guidance for the construction of the new Three Gorges locks in the future, as well as for the development of ships in the Three Gorges Hub.
Multi-Objective Optimization of Ship Passageway Layout Based on Pedestrian Transition Model
Authors: Zhao Jiutian , Wang Hao , Liang Fangyan , Xiao Tianli , Luo Liang 
Published: August 2024

Abstract
Along with the large-scale ship, the internal structure of the ship is more complex, the number of passengers on board increases, and the problem of large-scale personnel evacuation becomes more and more prominent. Nowadays, the research on total layout design mainly focuses on the comprehensive evaluation of total layout scheme, optimized design of local layout and layout optimization of compartments, while the research on the design and optimization of ship passageway layout is relatively less, and at the same time, the research on relevant ship passageway layout exists the problem that it only applies to the local layout of the ship or only gives a fixed form of passageway layout. In this paper, a new ship passageway layout optimization method is proposed to construct a multi-objective optimization model of ship passageway by combining with Pedestrian Transition Mode. This method can put forward or improve the design scheme of ship passageway layout in the early design stage of the ship, shorten the design cycle and improve the intelligent level of ship design. The example results show that the multi-objective optimization mathematical model for ship passageway layout proposed in this paper is feasible, and the comparison results show that our model effectively attenuates the peak crowd density and is more superior.
Safe Damping Factor for Non-Linear Cases of Subsea Equipment Installation
Authors: Salvador Lopes Filipe , Fernandes Antonio Carlos , Sena Sales Junior Joel 
Published: August 2024

Abstract
The vertical lowering of subsea equipment is one of the most used methods of installation. As the name suggests, it consists of vertically lowering the equipment using a crane on the installation ship. During the lowering, the cable’s length will change, leading to the vertical stiffness of the system not being constant. As the ship is subjected to environmental loads, its vertical motions will be transmitted to the equipment underwater. Therefore, different excitation’s frequency will be more critical depending on the water depth being studied.
When the excitation’s frequency is close to the natural frequency of the system, the equipment’s vertical motion is amplified, which might lead to the cable becoming slack. The slackness effect is succeeded by very high-tension values, usually known as snap loads, which can represent a serious risk to the installation.
This work shows that increasing the system’s damping is a way to reduce the tension values on the cable for a given environmental condition. Different damping factors can lead to different dynamic behaviors, which will have an impact on the tension values. It was seen that after the damping factor is sufficiently increased, the tension peaks on the cable will become almost constant, even after further increasing the damping. This value on which the tension peaks converge to a known and lesser value is what is referred to as safe damping factor on the title, as it can be used to determine the maximum tension peak expected to happen, allowing the increase of the operational window if a cable capable of withstanding this tension value is used.
An Elastically Moored Flexible Multibody Wave Energy Converter
Authors: Nag Chowdhury Debneil , De Chowdhury Swapnadip , Ghoshal Ritwik 
Published: August 2024

Abstract
This paper introduces a novel wave energy converter design that utilizes a concept for regulating displacement amplitude with an internal non-linear rotative gravity pendulum system. A standard wave energy converter, which operates as a cylindrical buoy floating in an ocean of finite depth and is tethered to a concrete foundation installed in the seabed, and subjected to regular waves. The buoy is equipped with an original internal non-linear rotative gravity pendulum system designed to control the heave motion of the buoy. This allows for the dynamic adjustment of wire tension, subsequently governing the power output of the buoy. Furthermore, this innovative design enables the buoy to adapt to a wide range of power requirements and environmental conditions. A mathematical model that employs potential theory and a linearized free-surface boundary condition is adopted to simulate the behavior of this elastically moored flexible multibody wave energy converter. The effectiveness of this design is thoroughly investigated through an extensive study. The influence of the mass and damping constants of the multibody device on the displacement response is also explored. A comparative analysis is performed numerically between devices with and without a parametric gravity pendulum exciting device. The study indicates the existence of both beat and prominent internal resonance phenomena, which warrant meticulous investigation in further studies. These findings have potentially significant implications for renewable energy production, particularly in coastal and offshore areas.
An Analytical Solution for Evaluating Structural Resistance of a Stiffened Plate Under Lateral Impact With Large Indentation
Authors: Zhang Yichi , Zhou Jiayou , Yuan Yuchao , Tang Wenyong 
Published: August 2024

Abstract
Ship collision accidents occur frequently despite the efforts of developing collision-avoidance technology and tools. The structural crashworthiness analysis is thus important and developing rapid prediction tools have been a hot field in the past decades. This paper presented a new analytical solution for assessing the structural resistance of a stiffened plate under lateral impact from a raked bow. Numerical simulations were firstly carried out to help identify the mechanisms of structural deformation of the stiffened plate from the side shell. The damage modes of the stiffened plate were categorized as three types with the continuous indenting of the bow. Multiple analytical formulas were derived to cover the process of damage evolution, including plate denting, plate rupture and plate tearing. Detailed analytical models for stiffeners were also developed for various deformation phases instead of using equivalent thickness method. Finally, an integrated method was developed based on the derived formulas for each single component. The integrated method innovatively considered the coupling effects and interactions between various structural members in the collision analysis by dynamically correcting some parameters. The method was verified against the numerical simulations of full-scale ship collisions through several typical scenarios and good accuracy was achieved. The newly developed method is valuable for crashworthiness design in the preliminary designing phase, especially for severe collision scenarios.
Development of a High Fidelity Multi-Agent Maritime Simulator
Authors: Ibrahim M. Mohammed , Deogaonkar Vallabh , Somayajula Abhilash 
Published: August 2024

Abstract
The maritime industry has experienced significant growth in autonomous systems in recent years, with substantial research dedicated to developing diverse algorithms for the autonomous navigation of surface vessels. To thoroughly gauge the credibility of such autonomy algorithms often requires evaluation across a diverse range of scenarios. Due to the vast number of potential scenarios that necessitate testing, it is impractical to conduct all these tests in a practical manner. Furthermore, these tests are not one-shot endeavors and need to be evaluated with the changing maneuvering characteristics of the vessel as it evolves over its operational years. This paper introduces the concept of a novel multi-agent, adaptive simulator designed specifically for testing various autonomy algorithms for surface vessels such as path planning and collision avoidance. The key highlight of the simulator lies in its potential to progressively improve the accuracy of the hydrodynamic models of the vessels present in the simulation.
The Effect of Post-Storm Reconsolidation on the Response of Monopile-OWT Systems in Clay
Authors: Aghedo Iwinosa O. , Charlton Tom S. , Rouainia Mohamed 
Published: August 2024

Abstract
Geotechnical processes related to offshore monopiles for supporting OWTs in soft clay involve intermittent episodic remoulding during storm events and reconsolidation during calm conditions. To assess the resulting response of monopiles, this study employs a three-dimensional finite element analysis. The methodology incorporates a kinematic hardening soil constitutive model within the critical state framework, calibrated against cyclic triaxial experiments and validated against the centrifuge test results on a 6m diameter monopile in soft clay subjected to multiple episodes of cyclic loading and reconsolidation. Thereafter, we investigate the performance of a reference 15MW OWT supported on a 10m diameter monopile in clay, subjected to three ten-minute storms of combined wind and wave loading representative of a 10-year return period, with reconsolidation periods between each storm. The results show a reduction in effective stress around the monopile during storms followed by recovery during reconsolidation, leading to a reduction in the level of monopile displacement accumulated in each subsequent storm event. This beneficial effect is overlooked in design practice, but can be anticipated through the approach presented here, which can form the basis for the validation of a digital twin that monitors the lifetime integrity of a monopile foundation.
On the Bending Responses of Adhesively Bonded Mechanically Lined Pipes
Authors: Yan Junhan , Yuan Lin 
Published: August 2024

Abstract
As a new type of CRA lined pipe, adhesively bonded mechanically lined pipe utilizes a glue layer between the inner and outer pipes to enhance the gripping between the two pipes. With the help of mechanical bonding and adhesive, the liner’s wrinkling and collapse have shown to be somewhat delayed, making this new type of product a more economical and efficient solution for offshore applications. However, the mechanical behavior and the design of key parameters of such a product are still less understood.
In this work, we developed a numerical framework to study the bending response of the adhesively bonded mechanically lined pipe (ABMLP), in which the hydraulic expansion-induced residual stresses and strains were considered for completeness. The pure bending characteristics of perfect and imperfect ABMLP, especially the evolution of local buckling of the liner, were carefully examined. Furthermore, the paper also preliminarily investigated the effect of important parameters of potential problems, such as the length of glue-free zones and the adhesive property variations.
Numerical Modelling and Analysis of a New Combined Concept of Floating Wind Turbine and Fish Farm Structure
Authors: Wan Ling , Tay Zhiyung , Shi Wei 
Published: August 2024

Abstract
To achieve better utilization of ocean space and energy, a new combined concept of floating wind turbine and fish farm structure is proposed. The four-pontoon semi-submersible platform is designed to support an offshore wind turbine and fish farm frames. The platform can be cost-effective, due to the sharing of the infrastructures, and the potential synergy from a proper combination. Open cage fish farm structure is designed to be modular, and can be flexible in dimension. In this work, coupled numerical model of the platform is established. Potential flow theory or panel model is used in the hydrodynamic property calculation. The slender fish farm frame structures are modelled by the Morison elements. Viscous effects are included through quadratic coefficients. Various aspects of wind turbine modelling, and fish farm modelling are discussed. Dynamic motion responses are studied, with a focus on the influences of the fish farm frames on the platform. Two scenarios, i.e., floating wind turbine with and without the existence of the fish farm frames, are specially investigated. Natural periods are presented, and dynamic performance of the two scenarios under wave conditions, wave + current condition, and wave + current + wind condition is investigated. Uncertainties in the analysis and future improvements are also discussed.
Experimental Study on the Collapse of Mechanically Lined Pipe Under External Pressure
Authors: Yuan Lin , Wang Chuangyi , Wang Xipeng 
Published: August 2024

Abstract
Mechanically lined pipes (MLP), known for their cost-effectiveness and reliability in transporting corrosive oil and gas, have increasing applications in offshore projects. The presence of the non-corrosive liner, although relatively thin, will increase the collapse capacity of MLP to some extent. In addition, the mechanical property changes induced by hydraulic plastic expansion during manufacturing are also expected to influence the buckling behavior of lined pipes. However, this problem is still less understood, and related studies about MLP collapse are mostly limited to numerical simulations instead of experiments.
In this work, we conducted a series of small-scale experiments on the mechanically lined tubes. The lined pipes, made of carbon steel Grade GB45 (AISI 1045) and T2 copper, are manufactured using a custom hydraulic expansion facility. The products have finished diameters of 50 mm and an overall D/t of 16.5, with 1.0 mm thickness for the liner. Afterward, intact and minorly dented specimens were collapsed under external pressure in a sealed hyperbaric chamber. The collapse pressure and final configuration of the tubes were recorded. In addition, the experimental results were reproduced by finite element models, which takes account for both the manufacture and collapse stages, and good agreement was reached.
Hydrodynamic Investigation on a Submerged Tunnel Suspended From Two Pontoons Under Various Immersion Depths
Authors: Song Yue , Sun Zhenxiang , Chen Nianzhong 
Published: August 2024

Abstract
In this paper, the hydrodynamic responses of a tunnel element suspended from two immersion pontoons have been studied by physical model tests in wave basin. A wide range of irregular waves is conducted on the tunnel immersing from the depth near the free surface to the depth near seabed. During each test, the six-DOF motion of the tunnel element and the immersion barge are measured in a simultaneous manner with two receiving terminals of an electromagnetic motion tracking system. Based on the measured data of scale 1:60, response spectra analysis is conducted to examine the coupled motion characteristics of the tunnel element for various immersion depths. Furthermore, to explore the coupled resonant properties of the tunnel immersion system, the coupled motion equation of the whole system is solved and the eigen modes and natural frequencies are obtained. The results showed that the mode frequencies of the coupled tunnel-barge system have a good corresponding relationship with the peak frequencies in the motion spectra. This demonstrates that the coupling mechanism between the tunnel element and immersion barges plays an important role in the motion responses of the tunnel. The increasing immersion depth have a significant effect on the coupling effects, and thus on the motion characteristics of the tunnel element.
Construction and Validation of a Two-Way Fluid-Structure Interaction Solver Under an Open-Source Framework
Authors: Sun Jia-Yu , Sun Shi-Li , Wang Shuang 
Published: August 2024

Abstract
The Fluid-Structure Interaction (FSI) issue is a complex and nonlinear process involving the interaction between a deformed structure and the surrounding fluid. In this work, we developed a novel high-fidelity, modular, open-source and user-friendly FSI simulation framework by coupling the well-established fluid solver OpenFOAM® with the structure solver CalculiX. The fluid solver solves unsteady RANS equations using a finite volume method on unstructured meshes. The hydrodynamic loads on the surfaces of the object are then passed to structural solver. The displacements and structural response of the object are efficiently computed and exchanged with the fluid solver through a finite element analysis. The coupling was implemented through the preCICE coupling library for partitioned multi-physics simulations, which treats the two dedicated solvers as ‘black boxes’ and provides data mapping between non-matching meshes. Two classical FSI test cases are presented, and the numerical results are compared with previously published laboratory tests and benchmark data, achieving a satisfactory agreement. This work provides an efficient tool under the open-source framework for Fluid-Structure Interaction simulation.
Repurposing Submarine Hydrocarbon Pipelines for Dense Phase CO2 Transport
Authors: Rulence Emilien , Husband Sean 
Published: August 2024

Abstract
Carbon Capture and Storage (CCS) will play a crucial role in the energy transition. Natural gas developments must continue for decades to meet growing energy demands and to concurrently enable the transition from fossil fuels to renewable energy generation. Stripping the CO2 from the natural gas and disposing it into depleted reservoirs will be essential to reduce harmful emissions during the transition. Many depleted offshore natural gas fields are planned for CCS. They will require a submarine pipeline that transports CO2 from an onshore processing facility to the field.
CO2 has been transported via onshore pipelines for several decades, however there is less global experience in the design, construction, and operation of submarine CO2 pipelines. In many cases the CO2 needs to be transported in dense phase for efficiency. The complex properties of dense phase CO2, combined with the technical and operational challenges of a carbon steel pipeline in a wet environment, create an engineering challenge that has only recently been uncovered. A potential attractive option is to repurpose existing hydrocarbon pipelines to transport dense phase CO2. This has significant benefits. There is no need to perform seabed route surveys, purchase linepipe materials, and construct a new pipeline. However, repurposing existing pipelines for dense phase CO2 transport is not always a feasible or safe option.
This paper utilizes the foundations outlined within the DNV industry standards to propose a high-level screening methodology that aims to quickly understand if existing hydrocarbon pipelines have the potential to be re-qualified for dense phase CO2 transport. Two case studies are presented to illustrate how this methodology can be applied, with different outcomes.
Optimization Study of Ship Speed Based on Membrane Computing Theory
Authors: Wang Hao , Zhang Yanbing , Xu Haoran , Wang Lizheng 
Published: August 2024

Abstract
In this paper, a speed optimisation algorithm based on membrane computing theory is proposed for Yangtze River bulk carriers. First, a ship energy consumption model is constructed and validated based on the improved Ayer’s method. Then a global optimization algorithm, called the membrane computing theory-based diffusion optimization algorithm (MC-DOA), is proposed, which is inspired by the double-membrane cell structure of chloroplasts and mitochondria as well as the phenomenon of particle diffusion, and makes use of a mixed-membrane structural system and four different particle searching strategies to search for global optimum values. Finally, a sailing speed optimization model is developed with the objective of optimal energy consumption and constraints such as specified sailing arrival time. In order to verify the effectiveness of the speed optimization algorithm, a 6700-ton bulk carrier on the Yangtze River is taken as the target ship, and a typical route from Chongqing to Shanghai is selected for the optimization test. The results show that the proposed speed optimization algorithm is able to solve the inland waterway speed optimization problem efficiently, and save the fuel consumption of the ship by optimizing the ship’s speed effectively.