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Comparison of two second-order sliding mode control algorithms for an articulated intervention AUV: Theory and experimental results Ocean Eng. (IF 3.068) Pub Date : 2021-01-14 Ida-Louise G. Borlaug; Kristin Y. Pettersen; Jan Tommy Gravdahl
An articulated intervention autonomous underwater vehicle (AIAUV) is a slender, multi-articulated underwater robot. Accurate trajectory tracking is essential for AIAUV operations. Furthermore, due to hydrodynamic and hydrostatic parameter uncertainties, uncertain thruster characteristics, unknown disturbances, and unmodelled dynamic effects, robustness is crucial. In this paper, we present a super-twisting
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Fatigue analysis of polycrystalline materials using Peridynamic Theory with a novel crack tip detection algorithm Ocean Eng. (IF 3.068) Pub Date : 2021-01-14 Ning Zhu; Cemal Kochan; Erkan Oterkus; Selda Oterkus
This study presents prediction of crack propagation in polycrystalline materials under cyclic loads using Peridynamic (PD) theory. The PD fatigue model utilizes the strain-load cycle (ε-N) data and introduces the “remaining life” of each bond calculated from its cyclic strain, which changes over time. The model also captures the traditional Paris law, which is widely used for computing the fatigue
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Myths and realities of endurance time analysis: Discussion/Comments Regarding “Seismic assessment of deep water bridges in reservoir considering hydrodynamic effects using endurance time analysis” by Yutao Pang, Li Cai, Wei He, and Li Wu; Ocean Engineering, 2020, 198:106846 Ocean Eng. (IF 3.068) Pub Date : 2021-01-14 Mohammad Amin Hariri-Ardebili; Siamak Sattar
This discussion is based on the paper by Pang et al. (2020) (hereafter identified as “the original authors” and “the original paper” or “the reference paper”). The original authors employed the endurance time analysis (ETA) and incremental dynamic analysis (IDA) techniques to investigate the probabilistic response of a deep water bridge in a reservoir. They derived multiple fragility curves using both
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Study on the cavitation effects induced by the interaction between underwater blast and various boundaries Ocean Eng. (IF 3.068) Pub Date : 2021-01-13 Z. Jin; C. Yin; Y. Chen; Y.D. Cui; B.C. Khoo; S. Jiao; H. Hua
The load of cavitation collapse is one of the main input loads to the structure subjected to underwater explosion. The cavitation effects near different boundaries are of particular importance in understanding the load mechanisms and designing the protective structures. In present study, a numerical model that couples a Runge Kutta Discontinuous Galerkin method, a finite element method and an isentropic
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Comparative study on hydrodynamic performance and induced pressure of new canard tandem propellers and conventional propellers Ocean Eng. (IF 3.068) Pub Date : 2021-01-12 Huilan Yao; Yong Liu; Huaixin Zhang; Qin Zhang
Thrust, efficiency, induced pressure on hull surface and negative pressure distribution on blade surface of five conventional propellers and twenty-eight tandem propellers were studied comprehensively by numerical method to assess the ability of two different types of propellers in dealing with efficiency, cavitation, vibration and noise problems. The flow field was simulated by solving RANS equations
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Direct damage index based on inverse finite element method for structural damage identification Ocean Eng. (IF 3.068) Pub Date : 2021-01-12 Mengying Li; Ziyan Wu; Haifeng Yang; He Huang
Structural damage identification is the core problem of structural health monitoring (SHM). The traditional damage detection methods are restricted in the practical applications, due to factors including the complete measured data and modal information required before and after damaged states. Strain damage indexes have attracted wide attention due to their high sensitivity to local damage. This paper
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Optimal design of longitudinal stiffeners of unsymmetric plate girders subjected to pure bending Ocean Eng. (IF 3.068) Pub Date : 2021-01-10 Seung-Eock Kim; George Papazafeiropoulos; Carlos Graciano; Viet-Hung Truong; Quang Thang Do; Zhengyi Kong; Quang-Viet Vu
This paper aims at investigating the optimum positions and the required flexural rigidity (γrq) of a single and two longitudinal web stiffeners of unsymmetric plate girders subjected to pure bending by using gradient-based optimization algorithms. The optimization procedure is performed into two steps: The first step is to maximize the bend-buckling coefficient kb generated from eigenvalue buckling
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Numerical investigation of local scour around a vibrating pipeline under steady currents Ocean Eng. (IF 3.068) Pub Date : 2021-01-08 Ming-ming Liu; Xin Jin; Lu Wang; Fan Yang; Jinbo Tang
A two-dimensional finite element numerical model was developed to predict local scour around a vibration submarine pipeline in steady current. The numerical model was based on incompressible two-dimensional Navier-Stokes equations with a Shear-Stress Transport (SST) k-ω turbulence model closure. The transportations of suspended load and the bed load were taken into consideration in the present numerical
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The hydroelastic analysis of marine propellers considering the effect of the shaft: Theory and experiment Ocean Eng. (IF 3.068) Pub Date : 2021-01-09 Donglin Zou; Jianghai Xu; Jing Zhang; Fangrui Lv; Na Ta; Zhushi Rao
At present, although there are a large number of studies on the hydroelastic analysis of ship propellers, almost all of them neglect the shaft, thus ignoring the influence of the structural coupling effect between the propeller and the shaft. Therefore, considering this coupling effect, a new hydrodynamic analysis model of propellers is established by using the boundary element method (BEM) coupled
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Coastal zone significant wave height prediction by supervised machine learning classification algorithms Ocean Eng. (IF 3.068) Pub Date : 2021-01-09 Demetris Demetriou; Constantine Michailides; George Papanastasiou; Toula Onoufriou
Explicit wave models and expensive sensor equipment capable of predicting and measuring wave parameters often carry a prohibitive computational and financial expense. To counter this, this paper proposes an alternative method for nowcasting coastal zone significant wave heights through the joint use of meteorological and structural data in the training of supervised machine learning models. In testing
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Research on high quality mesh method of armored umbilical cable for deep sea equipment Ocean Eng. (IF 3.068) Pub Date : 2021-01-08 Kun Xie; Yongping Jin; Youduo Peng; Guangping Liu; Buyan Wan
Most of the references are automatic mesh generation, but the accuracy of armored umbilical cable (AUC) analysis is not high enough. There is no detailed introduction about high-quality mesh generation method. Therefore, a high quality mesh method (hexahedral mesh generation method) for AUC for deep sea equipment is proposed in this paper. Hexahedral mesh generation method is often used in the analysis
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Parametric study and formula for SCFs of FRP-strengthened CHS T/Y-joints under out-of-plane bending load Ocean Eng. (IF 3.068) Pub Date : 2021-01-07 Hossein Nassiraei; Pooya Rezadoost
In this paper, the stress concentration factors (SCFs) in tubular T/Y-connections strengthened with fiber reinforced polymer (FRP) under OPB are investigated. For this aim, 263 FE models of T/Y-joints with FRP were generated and analyzed. In the FE models, the contact between the FRP sheets and the members was modeled. By using the generated FE models, the effect of the FRP layers, the brace inclination
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Research on self-propelled performance of multi-body system of wave-driven robot Ocean Eng. (IF 3.068) Pub Date : 2021-01-07 Weixin Zhang; Ye Li; Yulei Liao; Kaiwen Pan; Leifeng Wang
wave-driven robot is a flexible multi-body dynamic system driven by ocean waves. Self-propelled performance is an important index of wave-driven robot, which includes propulsion performance, resistance performance and rapidity of wave-driven robot, as well as its ability to capture and utilize ocean wave energy. However, the wave-driven robot belongs to flexible multi-body structure, whose dynamic
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Active control synthesis of nonlinear pitch-roll motions for marine vessels Ocean Eng. (IF 3.068) Pub Date : 2021-01-07 Sang-Do Lee; Sam-Sang You; Xiao Xu; Truong Ngoc Cuong
This paper investigates the dynamical analysis and control synthesis for fractional-order pitch-roll system of marine vessels under regular waves. Suppression of the effects of roll and pitch motions is critical in improving maneuverability and stability of marine vessels with ensuring the safety of cargo and comfort to sailors. The pitch-roll mode shows complex behaviours such as period-2 motion,
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Gas entrainment from gaseous supercavities: Insight based on numerical simulation Ocean Eng. (IF 3.068) Pub Date : 2021-01-07 Michael P. Kinzel; Jules W. Lindau; Robert F. Kunz
The understanding of the internal gaseous flow of artificially ventilated supercavities is developed using a locally homogenous, multiphase computational fluid dynamics model that is benchmarked using experimental data. The solutions indicate that gas leakage from a ventilated supercavity originates from the gaseous shear layers forming at the gas-water interface. Not only do these observations corroborate
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Mathematical modeling of arbitrary shaped harbor with permeable and impermeable breakwaters using hybrid finite element method Ocean Eng. (IF 3.068) Pub Date : 2021-01-07 Rupali; Prashant Kumar
A mathematical model is developed based on the application of permeable and impermeable breakwaters utilizing the mild slope equation (MSE) to analyze the wave amplification in an arbitrary shaped harbor with variable bathymetry. Finite element method (FEM) coupled with analytical approximation is described as Hybrid FEM, which is used to solve the MSE and Helmholtz equation in bounded and unbounded
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Seismic response of offshore composite caisson-piles foundation with different pile configurations and soil conditions in centrifuge tests Ocean Eng. (IF 3.068) Pub Date : 2021-01-07 Hao Zhang; Fayun Liang; Haibing Chen
A series of centrifuge shaking table tests were performed on a new type of foundation, the composite caisson-piles foundation (CCPF) which is recently suggested for the cross-sea bridge or offshore engineering, to investigate its seismic response. The CCPF model with 2 × 2 and 3 × 3 pile groups embedded in homogeneous clayey silt or layered soil consisting of dry sand underlain by clayey silt were
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Robust integral backstepping and terminal synergetic control of course keeping for ships Ocean Eng. (IF 3.068) Pub Date : 2021-01-06 Muhammad Muzammal Islam; Syed Ahmad Siffat; Iftikhar Ahmad; Muwahida Liaquat
Course keeping control of ships deals with the automation of their trajectories for which a better rudder action is required to control the ship heading to continuously remain at the desired reference despite of environmental disturbances like sea winds and sea waves. For this purpose, this paper proposes Robust Integral Backstepping, Synergetic, and Terminal Synergetic controllers for good course
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Hydro-elastic response of composite hydrofoil with FSI Ocean Eng. (IF 3.068) Pub Date : 2021-01-05 Temtching Temou Vanilla; Augier Benoit; Paillard Benoit
The present study investigates experimentally and numerically the impact of composite materials on hydro-elastic performances of a hydrofoil experiencing Fluid–Structure Interactions, and focus on the bend–twist coupling phenomenon. Four flexible hydrofoils piercing the free surface, with identical geometry of extruded plan-form, a constant NACA0015 section, are tested in a cantilevered configuration
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Theoretical analysis on vibration transmission control in a shaft-hull system excited by propeller forces via an active multi-strut assembly Ocean Eng. (IF 3.068) Pub Date : 2021-01-06 Xiling Xie; Dequan Yang; Di Wu; Zhiyi Zhang
An active multi-strut assembly is used to attenuate vibration transmission from the shaft to the hull of underwater vehicles induced by the propeller forces. The active assembly with embedded actuators is inserted between the stern bearing and the hull. First, the dynamic model of the shaft-hull system is developed using the Timoshenko beam theory and the FRF (Frequency Response Function)-based synthesis
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Simulation of extreme waves using coupled atmosphere-wave modeling system over the South China Sea Ocean Eng. (IF 3.068) Pub Date : 2021-01-06 Zhiyuan Wu; Jie Chen; Changbo Jiang; Bin Deng
A real-time two-way coupled atmosphere-wave model in the South China Sea (SCS) has been established based on the atmosphere model WRF and the wave model SWAN in this study. We implement a nested computational grid along the SCS in the SWAN model and utilize the WRF model to provide high-resolution mesoscale wind field and pressure field over the SCS under the influence of typhoons. The numerical simulation
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Comparative analysis on various components of heave damping for sandglass-type floating body Ocean Eng. (IF 3.068) Pub Date : 2021-01-06 Wen-hua Wang; Xiao-ming Ran; Zi-han Zhao; Yi Huang
For the new sandglass-type floating body with special shape, this paper mainly analyzes the characteristic of the heave damping and its corresponding components by computational fluid dynamics (CFD) method. Firstly, the convergence and accuracy of the CFD method to simulate the heave motion of sandglass-type floating body were validated along with the experimental data. Secondly, the numerical model
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Study on bubble collapse near a solid wall under different hypergravity environments Ocean Eng. (IF 3.068) Pub Date : 2021-01-06 Liangtao Liu; Ning Gan; Jinxiang Wang; Yifan Zhang
Bubble has significant applications in ocean engineering. Aiming at the difficulty of conducting the underwater explosion bubble experiment with large charge in deep water, this paper adopts a new way to deal with this problem. On the basis of similarity theory, it is found that by considering the scaling relationship of gravitational acceleration, the explosion bubble with small charge in shallow
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Deformation measurement of a monopile subject to vortex- induced vibration using digital image correlation Ocean Eng. (IF 3.068) Pub Date : 2021-01-06 Simon Tödter; Hassan el Sheshtawy; Jens Neugebauer; Ould el Moctar; Thomas E. Schellin
Monopile towers used for offshore wind turbines are sensitive to Vortex-Induced Vibration (VIV). Here, their structural response to VIV was experimentally investigated with models of a partially and a fully immerged offshore monopile. The partially and fully immersed model cylinders had aspect ratios of 18.75 and 28.13, respectively. They were subject to reduced velocities of up to 9.78 and 5.45, respectively
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A framework for transformation to nearshore wave from global wave data using machine learning techniques: Validation at the Port of Hitachinaka, Japan Ocean Eng. (IF 3.068) Pub Date : 2021-01-05 Sooyoul Kim; Tracey H.A. Tom; Masahide Takeda; Hajime Mase
The present study introduces a framework for predicting nearshore waves using two machine learning techniques of Group Method of Data Handling (GMDH) and Artificial Neural Network (ANN), trained with three global wave datasets of Japan Meteorological Agency (JMA), National Oceanic and Atmospheric Administration (NOAA), and European Centre for Medium-Range Weather Forecasts (ECMWF). Prior to our ultimate
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A new dynamic model of towing cables Ocean Eng. (IF 3.068) Pub Date : 2021-01-05 Samuel da Silva Gomes; Sebastião Cícero Pinheiro Gomes
This article proposes a new formalism for the dynamic modeling of a cable towing system, in which both the tugboat and the towed vessel are subject to forces from waves on the sea surface. The continuous flexibility of the cable is approximated by a discrete equivalent, formed by rigid links connected by fictitious elastic joints that allow elevation movements, since the dynamics are restricted to
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Analysis of ship maneuvering difficulties under severe weather based on onboard measurements and realistic simulation of ocean environment Ocean Eng. (IF 3.068) Pub Date : 2021-01-04 Qianfeng Jing; Kenji Sasa; Chen Chen; Yong Yin; Hironori Yasukawa; Daisuke Terada
The increasing demand for efficient, safe, and economic operation of ships has drawn attention to practical maneuvering behaviors for developing autonomous ships. Actual sailing conditions are reproduced to determine the relationship between environmental factors and ship steering records in rough seas. First, we generate realistic ocean environmental fields and analyze actual sea data. Then, we derive
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A frequency-time domain method for ship fatigue damage assessment Ocean Eng. (IF 3.068) Pub Date : 2021-01-04 Jingxia Yue; Ke Yang; Lihua Peng; Yulong Guo
Ships in ocean waves are suffered from cyclic wave loads which can cause fatigue damage to ship structures. Classification societies require owners to carry out fatigue assessment for ship structure for its potential great loss caused by fatigue failure. Currently there are many fatigue assessment methods including simplified method, deterministic method, spectral-based method and time domain method
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Uncertainties in return values from extreme value analysis of peaks over threshold using the generalised Pareto distribution Ocean Eng. (IF 3.068) Pub Date : 2021-01-04 Philip Jonathan; David Randell; Jenny Wadsworth; Jonathan Tawn
We consider the estimation of return values in the presence of uncertain extreme value model parameters, using maximum likelihood and other estimation schemes. Estimators for return value, which yield identical values when parameter uncertainty is ignored, give different values when uncertainty is taken into account. Given uncertain shape ξ and scale parameters of a generalised Pareto (GP) distribution
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Dynamics augmentation for high speed flying yacht hulls through PID control of foiling appendages Ocean Eng. (IF 3.068) Pub Date : 2021-01-02 C.L. Amoroso; A. Liverani; D. Francia; A. Ceruti
A numerical investigation is conducted in order to identify a PID control loop feedback scheme able to return dynamics augmentation and superior seakeeping characteristics in the application of high speed flying yacht hulls. An existing lumped parameters model based on general unsteady equations of motion is extended and implemented in combination with a regular basic ocean waves model, to conduct
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A novel conceptual design of a dynamically positioned floating wind turbine Ocean Eng. (IF 3.068) Pub Date : 2021-01-01 Shengwen Xu; Motohiko Murai; Xuefeng Wang; Kensaku Takahashi
Currently, all floating wind turbines served on the sea are positioned by the mooring system. A novel conceptual design of using the dynamic positioning system (DPS) to position the floating wind turbine is proposed in this paper. Certain benefit aspects of the proposed conceptual design are elaborated. A time domain simulation for the designed floating wind turbine is conducted to demonstrate its
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Prediction of cavitation and its mitigation techniques in hydraulic turbines - A review Ocean Eng. (IF 3.068) Pub Date : 2020-12-31 Brijkishore; Ruchi Khare; Vishnu Prasad
Cavitation is a major problem in the hydraulic reaction turbine because it damages turbine components, affects turbine performance and increases maintenance. Hence there is a need for further research and development on the minimization of cavitation in turbines based on previous research work. Cavitation occurs due to the fall in pressure below vapour pressure of water, which may be due to inappropriate
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A numeric study of the maneuverability of planing hulls with six degrees of freedom Ocean Eng. (IF 3.068) Pub Date : 2020-12-31 Roberto Algarín; Antonio Bula
A mathematical model studying the dynamic of planing hulls with six degrees of freedom is developed. The turning circle as well as the zigzag maneuvers are simulated with this model. The results are compared with CFD (computational fluid dynamics) simulations and experimental results reported by others authors with good agreement. A numerical experiment design was performed to evaluate the maneuverability
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Prediction and optimisation of fuel consumption for inland ships considering real-time status and environmental factors Ocean Eng. (IF 3.068) Pub Date : 2020-12-30 Zhi Yuan; Jingxian Liu; Qian Zhang; Yi Liu; Yuan Yuan; Zongzhi Li
The information about ships’ fuel consumption is critical for condition monitoring, navigation planning, energy management and intelligent decision-making. Detailed analysis, modelling and optimisation of fuel consumption can provide great support for maritime management and operation and are of significance to water transportation. In this study, the real-time status monitoring data and hydrological
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3D flow structures behind a wall-mounted short cylinder Ocean Eng. (IF 3.068) Pub Date : 2020-12-30 Hiroka Rinoshika; Akira Rinoshika; Jin-Jun Wang; Yan Zheng
A high-resolution Tomographic particle image velocimetry (Tomo-PIV), which consists of four high-resolution double-exposure CCD cameras, was used to measured three-dimensional (3D) flow structures behind a wall-mounted short cylinder of an aspect ratio 1 at Reynolds number 10,720 in a water tunnel. Based on the measured instantaneous 3D velocity distribution, 3D velocity fields, the vorticity, the
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Robust depth control of a hybrid autonomous underwater vehicle with propeller torque's effect and model uncertainty Ocean Eng. (IF 3.068) Pub Date : 2020-12-31 Huy Ngoc Tran; Thanh Nguyen Nhut Pham; Sik Hyeung Choi
This paper presents a study of depth tracking controller design for a hybrid AUV in the presence of model uncertainty and propeller torque's effect. Firstly, the six degrees of freedom (6-DOF) nonlinear equations of motion, as well as the operating mechanisms and specific characteristics of the hybrid AUV, are described. Subsequently, the model for depth-plane is extracted by decoupling and linearizing
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Physical and numerical modeling of random wave transformation and overtopping on reef topography Ocean Eng. (IF 3.068) Pub Date : 2020-12-31 Ye Liu; Shaowu Li; Zhiling Liao; Kun Liu
Widespread flooding of reef-fringed islands demonstrates the insufficient protection provided by reef topographies and suggests the necessity of artificial structures for hazard prevention and mitigation. As an indicator of the structural protection efficiency, the wave overtopping rate is difficult to estimate in reef environments because hydrodynamics over reefs violate the application conditions
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Influence of trench geometry on fatigue response of steel catenary risers by using a boundary layer solution on a sloped seabed Ocean Eng. (IF 3.068) Pub Date : 2020-12-30 Rahim Shoghi; Celso P. Pesce; Hodjat Shiri
Previous studies have shown that the geometry of the trench affects the fatigue response of steel catenary risers (SCR). Fatigue performance of SCR in the touchdown zone (TDZ) has been investigated in several studies, sometimes leading to contradictory results, with no coherent agreement regarding if the effect of the trench on fatigue performance of SCR would be beneficial or detrimental. This paper
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Fatigue inspection and maintenance optimization: A comparison of information value, life cycle cost and reliability based approaches Ocean Eng. (IF 3.068) Pub Date : 2020-12-30 Guang Zou; Michael Havbro Faber; Arturo González; Kian Banisoleiman
Fatigue cracks increase structural failure risk and timely maintenance is very important. Maintenance planning is often formulated as a probabilistic optimization problem, considering uncertainties in structural and load modelling, material properties, damage measurements, etc. A decision rule or strategy, e.g. condition based maintenance (CBM), needs to be set up, and then an optimal maintenance criterion
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A literature survey of broken ice-structure interaction modelling methods for ships and offshore platforms Ocean Eng. (IF 3.068) Pub Date : 2020-12-30 Mohammed Islam; Jason Mills; Robert Gash; Wayne Pearson
Numerical modelling present an alternative to the more industry-accepted full-scale trials and physical model tests for predicting ice actions on ships and offshore platforms in a broken ice-field. Before a method is developed or adopted, it is essential to survey the existing methods that modelled relevant aspects of ice-ship interaction processes. This work presents an extensive literature survey
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Numerical analysis of the Cargo Transfer Vessel offloading operation in a Brazilian oil field Ocean Eng. (IF 3.068) Pub Date : 2020-12-30 Eduardo A. Tannuri; Alex S. Huang; Asdrubal N. Queiroz Filho; Marcos D. Ferreira; Fábio M. Passarelli; Pål B. Korneliussen; Petter Stuberg
In a new concept of offloading operation, the oil from a spread moored FPSO is transferred to a conventional Tanker with an intermediate Cargo Transfer Vessel (CTV) equipped with a DP system. A comprehensive numerical analysis of the CTV offloading operation is here developed considering the sea states in the Libra Field, Brazil. First, the environmental loads on the vessels were estimated. Current
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Numerical analysis on the effect of wave boundary condition in storm wave and surge modeling for a tropical cyclonic condition Ocean Eng. (IF 3.068) Pub Date : 2020-12-30 C. Gowri Shankar; Manasa Ranjan Behera
In a swell dominated region like the Northern Indian Ocean basin, the effect of pre-existing waves will play a significant role in the non-linear wave-wave interactions during cyclonic conditions, where the sea is dominated with high-frequency waves. Hence, to include such complex phenomenon into the numerical model, the present study aims at forcing a pre-run two-dimensional wave spectral output from
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The influence of regular wave and irregular wave on the mechanical characteristics of a triple-cylinder bundle structure Ocean Eng. (IF 3.068) Pub Date : 2020-12-30 Zhihao Zhang; Jiahuang Tu; Yongkang He; Zhaolong Han; He Yang; Dai Zhou; Shixiao Fu
By using the open source DualSPHysics, the interaction between wave and a triple-cylinder bundle structure is numerically investigated. The wave is generated by applying the predefined function to the wave maker, and the free surface and the velocity of the regular wave and irregular wave are compared with the theoretical data at the measuring point. To verify the feasibility of the numerical method
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Response of a self-powered offshore floating support structure with an OWC for powering a LIDAR device Ocean Eng. (IF 3.068) Pub Date : 2020-12-30 Nuno Mathias; Rebeca Nunes Marini; Tiago Morais; Pedro Luís; Mário Vaz; Paulo Rosa-Santos
To give an effective response to the increasing demand to characterise wind availability and intensity for the installation of future offshore wind farms, SPAR buoy OWCs with LIDAR present a clear benefit, due to their stability, mechanical and operational simplicity and lower cost, when compared to wind measuring towers, serving as an alternative to the latter, mainly for deep water. This paper proposes
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Refinement of integrated formula of wave overtopping and runup modeling Ocean Eng. (IF 3.068) Pub Date : 2020-12-30 Masatoshi Yuhi; Hajime Mase; Sooyoul Kim; Shinya Umeda; Corrado Altomare
This study attempts to refine a model named the Integrated Formula of Wave Overtopping and Runup Modeling (IFORM) to improve the prediction performance of mean wave overtopping discharge for a broader range of installation conditions. The empirical formula describing the relation between overtopping discharge and maximum runup has been re-examined. A set of piecewise formulas is implemented in the
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On the flow field induced by two counter-rotating propellers at varying load conditions Ocean Eng. (IF 3.068) Pub Date : 2020-12-29 Alessandro Capone; Fabio Di Felice; Francisco Alves Pereira
The hydrodynamics of the flow between and in the wake of contra-rotating propellers is investigated experimentally via Particle Image Velocimetry (PIV) at different advanced coefficients. Results show that the flow dynamics is deeply influenced by the interplay between the two systems of helical vorticity that develop in the wake. The forward and aft propellers’ slipstream structure is analyzed in
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Study of three-dimensional air gun bubble pulsation and the surrounding fluid pressure with finite volume method Ocean Eng. (IF 3.068) Pub Date : 2020-12-29 S. Zhang; B.C. Khoo; A.-M. Zhang
Air guns can be used for seabed resource exploration, shock testing of naval vessels, polar ice breaking, etc. The study of air-gun bubble pulsation and near-field pressure is of great significance. In order to analyze the dynamic behavior and pressure characteristics of air gun bubble in detail and quantitatively, this study used the finite volume and volume of fluid methods to establish a compressible
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Real-time deterministic prediction of wave-induced ship responses based on short-time measurements Ocean Eng. (IF 3.068) Pub Date : 2020-12-29 Tomoki Takami; Ulrik Dam Nielsen; Jørgen Juncher Jensen
This paper studies real-time deterministic prediction of wave-induced ship motions using the autocorrelation functions (ACFs) from short-time measurements, namely the instantaneous ACFs. The Prolate Spheroidal Wave Functions (PSWF) are introduced to correct the large lag time errors in the instantaneous sample ACF, together with a modification of the autocorrelation (AC) matrix for ensuring its positive
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Effect of pipeline-seabed gaps on the vertical forces of a pipeline induced by submarine slide impact Ocean Eng. (IF 3.068) Pub Date : 2020-12-28 Ning Fan; Fauzan Sahdi; Wangcheng Zhang; Tingkai Nian; Mark F. Randolph
In recent years, the interaction between submarine slide runout and offshore pipelines has received extensive attention, based on the need to protect pipelines crossing regions susceptible to submarine slides. The interaction force between the slide material and a pipeline may be resolved into horizontal and vertical components, but with most attention to date focusing on the former while the latter
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A deep supervised learning approach for condition-based maintenance of naval propulsion systems Ocean Eng. (IF 3.068) Pub Date : 2020-12-29 Tarek Berghout; Leïla-Hayet Mouss; Toufik Bentrcia; Elhoussin Elbouchikhi; Mohamed Benbouzid
In the last years, predictive maintenance has gained a central position in condition-based maintenance tasks planning. Machine learning approaches have been very successful in simplifying the construction of prognostic models for health assessment based on available historical labeled data issued from similar systems or specific physical models. However, if the collected samples suffer from lack of
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Investigation on total adjustment of the transducer and seafloor transponder for GNSS/Acoustic precise underwater point positioning Ocean Eng. (IF 3.068) Pub Date : 2020-12-29 Shuang Zhao; Zhenjie Wang; Zhixi Nie; Kaifei He; Ning Ding
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DEM analysis of the plugging effect of open-ended pile during the installation process Ocean Eng. (IF 3.068) Pub Date : 2020-12-29 Lichen Li; Wenbing Wu; Hao Liu; Barry Lehane
Mechanisms governing the sand plug behavior inside an open-ended pile are examined using the discrete element method. A series of numerical pile penetration tests have been conducted by considering the influence of soil density, pile geometry and installation method. A novel sample generation method, based on the replication of unit cell, is applied to produce a large and homogeneous sample efficiently
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Frictional effect on circular armour wire lateral buckling in umbilicals Ocean Eng. (IF 3.068) Pub Date : 2020-12-29 Xiaotian Li; Murilo Augusto Vaz
The present paper addresses the frictional effect on the circular armour wire lateral buckling in an umbilical for wet annulus condition. A nonlinear static finite element model is developed where only one single circular armour wire is simulated and the contact interface with the neighboring layer is represented by a deformable rigid toroid surface. The isotropic Coulomb friction model regularized
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Different closure patterns of the hollow cylinder cavities with various water-entry velocities Ocean Eng. (IF 3.068) Pub Date : 2020-12-28 Yu Hou; Zhengui Huang; Zhihua Chen; Zeqing Guo; Lei Han
The vertical water-entry processes of a hollow cylinder with three different velocities are investigated both numerically and experimentally. Three different closure patterns and flow characteristics of the air-entraining cavities induced by water-entry processes are discovered and discussed. Our results show that three different closure patterns appear with the increase of entry velocity, the deep-closure
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Numerical investigation of marine propeller underwater radiated noise using acoustic analogy Part 2: The influence of eddy viscosity turbulence models Ocean Eng. (IF 3.068) Pub Date : 2020-12-28 Savas Sezen; Taner Cosgun; Ahmet Yurtseven; Mehmet Atlar
The present study focuses on the impact of eddy viscosity turbulence models on the benchmark INSEAN E779A marine propeller hydroacoustic performance under non-cavitating and open water conditions. In the numerical calculations, Realisable k-epsilon (k-ε), k-ω Shear Stress Transport (k-ω SST) and Spalart-Allmaras turbulence models, which are widely used in hydrodynamic fields, are selected. Hydroacoustic
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Studies on model-scale ice using micro-potential-based peridynamics Ocean Eng. (IF 3.068) Pub Date : 2020-12-26 Renwei Liu; Yanzhuo Xue; Duanfeng Han; Baoyu Ni
This paper represents a numerical scale model of ice used to simulate the model experiment of ice-ship and ice-structure interaction scenarios. The micro-potential-based peridynamic formulations proposed in [7] are used to simulate the deformation and fracture of model-scale ice. In this configuration, a square measure of the bond length change is employed and validated with the finite element method
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Analytical and numerical study on lateral buckling of imperfect subsea pipelines with nonlinear lateral pipe-soil interaction model Ocean Eng. (IF 3.068) Pub Date : 2020-12-25 Zhenkui Wang; Yougang Tang; C. Guedes Soares
The nonlinear pipe-soil interaction model and the initial imperfections are predominantly factors that affect the lateral buckling behaviour of subsea pipelines with a high-temperature. In this study, mathematical models, taking these two factors into account, are proposed to simulate lateral buckling of subsea pipelines. Analytical solutions are derived from the assumption of rigid-plastic pipe-soil
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Experimental study on vertical water entry of twin spheres side-by-side Ocean Eng. (IF 3.068) Pub Date : 2020-12-25 Xu Wang; Xujian Lyu
The cavity dynamics and trajectories of twin spheres vertically entering water side-by-side are investigated experimentally for different time intervals and several lateral distances at initial velocities from 14.1 m/s to 15.2 m/s, with the diameter (D) based Froude number varying from 37.1 to 40.0. A high-speed photograph system and an image processing method are employed to obtain the features of
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Effects of duct parameter on pump-jet propulsor unsteady hydrodynamic performance Ocean Eng. (IF 3.068) Pub Date : 2020-12-25 Qiaogao Huang; Han Li; Guang Pan; Xinguo Dong
This work aims to investigate the effects of duct parameter on the open water performance of pump-jet propulsor. Five duct parameters are considered, including the length-diameter ratio, the incidence angle, the shrinkage ratio of duct inlet, the expansion ratio of duct outlet and the tip clearance ratio. Based on the mesh verification, a brief analysis of the PJP unsteady propulsion performance is
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Spectral Wave Explicit Navier-Stokes Equations for wave-structure interactions using two-phase Computational Fluid Dynamics solvers Ocean Eng. (IF 3.068) Pub Date : 2020-12-25 Zhaobin Li; Benjamin Bouscasse; Guillaume Ducrozet; Lionel Gentaz; David Le Touzé; Pierre Ferrant
This paper proposes an efficient potential and viscous flow decomposition method for wave-structure interaction simulation with single-phase wave models and two-phase Computational Fluid Dynamics (CFD) solvers. The potential part - represents the incident waves - is solved with spectral wave models; the viscous part - represents the complementary perturbation on the incident waves - is solved with
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