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Determination of hydrodynamic derivatives of an ocean vehicle using cfd analyses of synthetic standard dynamic tests Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-22 Javad Amini Foroushani; Majid Sabzpooshani
A synthetic method of dynamic test for identifying hydrodynamic coefficients (HCs) of an ocean vehicle has been proposed. The methodology consists of simulating various planar motion mechanism (PMM) tests simultaneously in a single numerical analysis. As a technical method, a stationary numerical domain has been used. Therefore, non-inertial forms of the fluid flow governing equations have been solved
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A numerical method to compute global resonant vibrations of ships at forward speed in oblique waves Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-20 Malte Riesner; Ould el Moctar
Resonant wave-induced vibrations of a ship hull girder, known as “springing”, is an important issue when addressing fatigue aging of the steel structure. To compute resonant wave-induced vibrations, fluid-structure interactions and associated structural and hydrodynamic properties need to be addressed. This paper introduces a time-domain numerical method that predicts higher-order springing taking
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Impact of two-dimensional seepage flow on sediment incipient motion under waves Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-19 Hualing Zhai; Dong-Sheng Jeng; Zhen Guo; Zuodong Liang
A small seepage could cause significant changes to the hydrodynamic gradient and further enhance the sediment incipient motion and scour. However, most previous studies either ignored the influence of seepage or only considered the upward seepage in the prediction of sediment incipient motion. In this paper, a modified Shields number considering the two-dimensional seepage was derived. The analytical
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Numerical simulation of wave interaction with porous structures Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-19 Ebrahim Jafari; Masoud Montazeri Namin; Peyman Badiei
The economical design of rubble mound structures namely breakwaters can be facilitated by means of an accurate simulation of interactions between the porous media and the passing currents and waves, to assure the safe economical design of these structures. Unlike most of the previous studies, the present study dealt with the development of a more realistic simulation by simultaneous consideration of
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Hydraulic expansion of lined pipe for offshore pipeline applications Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-19 Lin Yuan; Stelios Kyriakides
Carbon steel pipe lined with a thin layer of a corrosion resistant alloy is an economical product used in offshore pipelines that carry corrosive hydrocarbons. The liner and carrier pipe are mechanically expanded together so that on unloading they end up in interference contact. The contact pressure that develops is essential for keeping the composite pipeline intact under bending and axial loads experienced
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Experimental and numerical investigation on cavity formation from large rectangular spudcan penetration in clay Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-17 Lindong Fan; Pan Gao; Fei Wang; Menglan Duan
At present, the research on the cavity formed by spudcan penetration is based on two-dimensional axisymmetric analysis of circular spudcans, and it is doubtful whether the results could be applicable to rectangular spudcans. In this paper, centrifuge experiments and finite element analysis are combined to study the penetration process of large scale rectangular spudcans in the clay with undrained shear
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Scaling strategies for multi-purpose floating structures physical modeling: state of art and new perspectives Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-15 Carlo Ruzzo; Sara Muggiasca; Giovanni Malara; Federico Taruffi; Marco Belloli; Maurizio Collu; Liang Li; Giulio Brizzi; Felice Arena
Multi-purpose floating platforms are emerging as a promising concept in ocean engineering applications, thanks to their capability of ensuring system integration, cost reduction and modularization. However, their increasing complexity requires the development of numerical tools, which need to be validated experimentally through adequate physical models. New challenges hence arise, since the subsystems
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Investigation of moonpools as pitch motion reducing device Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-13 Lars Mikkel Utnes Reiersen; Trygve Kristiansen; Babak Ommani; Arnt Fredriksen
Moonpools as a device for reducing pitch motion is investigated experimentally, numerically and by an approximate theory. A two-dimensional study is carried out of a rectangular body with two moonpools. Forced heave and pitch motion, as well as freely floating body in regular waves are studied. The body geometry is varied; two drafts and five different moonpool inlet configurations are considered;
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CFD approach to heave damping of spar with heave plates with experimental validation Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-13 Mahesh J. Rao; S. Nallayarasu; S.K. Bhattacharyya
Spar, tension leg platform, and semi-submersibles use heave plates to reduce heave response by increasing heave damping and added mass. Conventional practice is to use a linear damping ratio, which is typically obtained from free heave decay tests or Computational Fluid Dynamics (CFD) simulations. However, with the addition of heave plates, the system damping becomes nonlinear. Understanding such nonlinear
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Hydrodynamic performance of a continuous floating bridge with heave plates Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-11 Yikuan He; Ji Wenyu; Jia Ying; Bing Han
This paper establishes a two-dimensional mathematical model of a continuous floating bridge with heave plates under linear monochromatic waves. Based on linear potential flow theory, the fluid domain is divided into two regions. The analytical equations for the rigid floating bridge considering the heave plate effect are derived from the boundary conditions. The wave force, added mass and damping coefficient
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An improved adaptive integral line-of-sight guidance law for unmanned surface vehicles with uncertainties Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-12 Yixin Su; Lili Wan; Danhong Zhang; Fanrong Huang
An improved adaptive integral line-of-sight guidance law and path following control system for Unmanned Surface Vehicles (USVs) with uncertainties is proposed in this paper. The dynamic equations of the tracking errors are established in the Serret-Frenet coordinate system with the consideration of the time-varying ocean currents. In order to eliminate tracking errors, three adaptive variables are
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Numerical simulation of wave run-up on four cylinders in a square configuration Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-10 Weiyi Chen; Yangyang Gao; Lizhong Wang; Zhen Guo; Bin Wang
A series of numerical simulations of wave run-up on four-cylinder array is performed at different spacing ratios 1.5 ≤ L/D ≤ 4.25, where L is the center-to-center distance between the adjacent cylinders and D is the cylinder diameter. The effects of spacing ratio and wave steepness on the wave run up ratio and wave force on the four cylinders are investigated. The results show that with variation of
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Nonlinear integrated dynamic analysis of drill strings under stick-slip vibration Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-08 Mohammad Javad Moharrami; Clóvis de Arruda Martins; Hodjat Shiri
Stick-slip torsional vibration raising from bit-formation contact is a catastrophic dynamic phenomenon occurring in deep-water oil and gas drilling systems. The torsional vibrations can result in premature fatigue failure of drilling equipment and reduce drilling efficiency. Thus, studying the dynamics of the system is a vital key to identify the roots of the vibration and establish appropriate mitigation
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Modelling an energetic tidal strait: investigating implications of common numerical configuration choices Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-07 Lucas Mackie; Paul S. Evans; Magnus J. Harrold; Tim O`Doherty; Matthew D. Piggott; Athanasios Angeloudis
Representation of the marine environment is key for reliable coastal hydrodynamic models. This study investigates the implications of common depth-averaged model configuration choices in sufficiently characterising seabed geometry and roughness. In particular, applications requiring a high level of accuracy and/or exhibiting complex flow conditions may call for greater detail in marine environment
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Numerical investigation on bearing capacity of OWT foundation with large diameter monopile under Seismic load Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-07 Qiyi Zhang; Yuan Zhang; Haodi Lin; Liang Feng
Dynamic characteristics of seabed soil under seismic load arevery important for the overall stability of the offshore wind turbine foundation. In this study, the horizontal bearing capacity and its corresponding soil deformation around the large-diameter monopile, where withstandsa transient high frequency seismic load, are simulated using a numerical method. During the numerical analysis in this paper
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Analysis of tensile response of flexible pipe with ovalization under hydrostatic pressure Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-06 Xiaohua Zhu; Qinglong Lei; Yu Meng; Xiaoxuan Cui
Flexible pipes play an important role in the transportation of oil and gas from the seabed to floating production units. They are also employed to inject water or gas into offshore wells. In deep-sea oil and gas extraction, flexible pipes must be able to withstand very high tensile and hydrostatic pressures. In this paper, an equivalent method is used to represent the complex carcass layer and the
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PORO-FSSI-FOAM model for seafloor liquefaction around a pipeline under combined random wave and current loading Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-04 Zuodong Liang; Dong-Sheng Jeng
In this study, unlike most previous investigations have limited to the regular wave conditions or combined wave and current conditions, a numerical model for seabed response around a pipeline in a trenched layer due to random waves is established. Three different wave spectra including the JONSWAP spectrum, Bretchneider–Mitsuyasu spectrum and Pierson–Moscowitz spectrum are considered in the present
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Wave power absorption by an oscillating water column (OWC) device of annular cross-section in a combined wind-wave energy system Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-05 Peiwen Cong; Bin Teng; Wei Bai; Dezhi Ning; Yingyi Liu
This paper deals with a new combined concept consisting of an oscillating water column (OWC) device and an offshore wind turbine for the multi-purpose utilization of offshore renewable energy resources. The wind turbine is supported by a monopile foundation, and the attached OWC is coaxial with the foundation. Within the chamber, the exterior shell of the OWC and the monopile foundation are connected
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Approach-angle-based three-dimensional indirect adaptive fuzzy path following of under-actuated AUV with input saturation Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-04 Jialei Zhang; Xianbo Xiang; Lionel Lapierre; Qin Zhang; Weijia Li
In this paper an approach-angle-based three-dimensional path-following control scheme has been proposed for underactuated Autonomous Underwater Vehicle (AUV) which experiences unknown actuator saturation and environmental disturbance. First, the path-following error dynamic model is derived based on the principle of relative motion which was followed by the design of approach-angle-based guidance law
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Laboratory tests on a hybrid SDR approach for jacket platforms via improved dynamic-reduction system Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-04 Farhad Hosseinlou
The improvement of robust skills for early defect recognition for fixed marine structures is crucial to avoid the possible catastrophe caused by structural degradation. This paper presents an approach for defect recognition based on vibration measurements that is capable of detecting the defect to individual members of offshore jacket platforms, when limited, spatially incomplete modal datum is available
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Wave radiation by a sphere in three-layer fluid Appl. Ocean Res. (IF 2.753) Pub Date : 2021-01-01 Dilip Das; Manomita Sahu
Using linear water wave theory, we consider the wave radiation (both heave and sway) by a sphere submerged in a three-layer fluid consisting of a layer of finite depth bounded above by a fresh water of finite depth with free surface and below by an infinite layer of water of greater density. The sphere is submerged in either of the three-layers. Each problem is reduced to an infinite system of linear
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Impact of heavy biofouling on a nearshore heave-pitch-roll wave buoy performance Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-30 Ricardo M. Campos; Hafizul Islam; Tobias R.S. Ferreira; C. Guedes Soares
The impact of biofouling is investigated on the accuracy of the records of a wave buoy moored in shallow water. The effects of biofouling on the vertical and horizontal motions of the buoy are analyzed through check factors. Regarding the heave motion, the most critical frequencies of the power spectrum are identified, and selected to run CFD simulations to further evaluate the hydrodynamic impact
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Variable-structure filtering method for an unmanned wave glider Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-31 Li Yiming; Li Ye; Pang Shuo
The unmanned wave glider (UWG) comprises an underwater glider and surface float connected by an umbilical cord. It is a highly adaptable marine vehicle with the advantages of low cost, low power consumption, and long endurance. At present, research on UWG filtering is still immature and not fully utilized. This paper proposes a variable-structure filtering method based on the double-body coupled yaw
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Design of a Hydrokinetic Turbine Diffuser Based on Optimization and Computational Fluid Dynamics Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-30 T.J. Rezek; R.G.R. Camacho; N. Manzanares Filho; E.J. Limacher
This work presents an optimization study for designing a shrouded turbine diffuser. The goal of the study was to obtain the geometry of the hydrofoil shaped diffuser which maximizes the hydraulic power of a turbine with a given set of constraints. The optimization process has been based on an automatic cycle of geometry modification, meshing and CFD analysis of the flow field, including a loaded diffuser
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Dynamic impedance of monopiles for offshore wind turbines considering scour-hole dimensions Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-29 Hao ZHANG; Fayun LIANG; Hanbo ZHENG
This study presents an effective solution to evaluate the dynamic impedances of scoured monopiles for offshore wind turbines in a wide excitation frequency range, which can properly account for both the effects of the scour-hole dimensions as well as of the soil stress histories, and the evaluation of these complex-valued impedance functions can be later used to take into account the soil-structure
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Experimental analysis of hydrodynamic forces on net panel in extreme waves Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-29 Tiao-Jian Xu; Guo-Hai Dong; Ming-Fu Tang; Jun Liu; Wei-Jun Guo
As fish farms move from nearshore region to open sea, understanding the hydrodynamic force on net structures in extreme waves plays a significant role in the design of offshore aquaculture structures. In this study, a series of experiments on different types of net panels in extreme waves were conducted in a wave flume. The dispersive focusing method with the constant steepness spectrum was adopted
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Artificial neural network for the prediction of shoreline changes in Narrabeen, Australia Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-29 Saeed Zeinali; Maryam Dehghani; Nasser Talebbeydokhti
Shorelines around the world are of great importance because of their role in people's lives. Therefore, understanding its behavior seems to be vital. Shoreline changes and its realignments are highly nonlinear and finding a method in such a way that it could model its patterns would be very useful. ANN's are popular methods, as they have been applied to numerous problems. In this study, recurrent ANNs
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Attitude control of aerial and underwater vehicles using single-input FUZZY P+ID controller Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-29 Qi Chen; Daqi Zhu; Zhaobing Liu
This paper considers the attitude control problem of a new class of aerial and underwater vehicles with quadrotor structures. A novel single-input FUZZY P+ID attitude controller is proposed to improve the trans-media performance of the aerial and underwater vehicle. The proposed FUZZY P+ID controller has a unique feature to deal with the nonlinear uncertainties using a set of fuzzy rules from experts
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Subsea pipeline leak inspection by autonomous underwater vehicle Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-29 Hongwei Zhang; Shitong Zhang; Yanhui Wang; Yuhong Liu; Yanan Yang; Tian Zhou; Hongyu Bian
Faced with the difficulty in finding and locating leakage points of submarine pipelines timely as well as the high cost of pipeline routine inspection, a scheme using autonomous underwater vehicle (AUV) equipped with multibeam echo sounder (MBES) and forward looking sonar (FLS) for automatic inspection of submarine pipelines was developed. In the process of inspection, the AUV maintains autonomous
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Effect of design configuration on structural response of longline aquaculture in waves Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-26 Dejun Feng; Ang Meng; Ping Wang; Yanbo Yao; Fukun Gui
The submerged deep-water longline aquaculture facility is known as a typical, flexible multi-degree-of-freedom offshore structure. Effects of layout concepts of the dropper weight, the upper buoy pattern and the incident wave angle on longline aquaculture systems have been studied by means of numerical modellings and conducting scaled model experiments. The results have showed that the dropper weight
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CFD prediction of ship seakeeping behavior in bi-directional cross wave compared with in uni-directional regular wave Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-26 Songxing Huang; Jialong Jiao; Chaohe Chen
The seakeeping behavior of a vessel in multi-directional wave differs significantly from that in uni-directional wave. Given that a vessel operates in multi-directional or short-crested waves during its whole service period, it is important to have a better understanding of the influence of wave directionality on ship seakeeping performance. In this study, CFD method is used to simulate ship motions
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Derivation of settling velocity, eddy diffusivity and pick-up rate from field-measured suspended sediment concentration profiles in the horizontally uniform but vertically unsteady scenario Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-23 Shaotong Zhang; Peter Nielsen; Pierre Perrochet; Beibei Xu; Yonggang Jia; Mingzheng Wen
Accurate determinations of sediment settling velocity (ws), eddy diffusivity (Ds), and pick-up rate p(t) from available field data are vital for engineering calculations or numerical simulations of coastal processes. Existing methods to determine these parameters are normally based on the assumption of a steady equilibrium that ignores the “phase lag” and “amplitude damping” effects of a diffusing
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Effects of stiffness and configuration of brace-viscous damper systems on the response mitigation of offshore jacket platforms Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-22 Mostafa Vaezi; Ali Pourzangbar; Manouchehr Fadavi; Seyyed Mahmoud Mousavi; Peyman Sabbahfar; Maurizio Brocchini
We investigate the effects of a brace-viscous damper system on the dynamic response of offshore platforms. To do this, offshore jacket platforms with various distributions and three different configurations of brace-viscous damper systems - toggle, chevron, and diagonal configurations - and a wide range of brace stiffness are numerically modelled under the loading of irregular waves in ANSYS software
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Surface wave interactions with submerged horizontal viscoelastic sheets Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-21 Dharma K.K. Sree; Sourav Mandal; Adrian Wing-Keung Law
In this study, the surface wave interactions with submerged horizontal viscoelastic sheets of varying rheological properties are investigated both experimentally and analytically. In the experiments, we adopt the novel development in preparing finite length viscoelastic sheets with different rheological properties using oil-doped polydimethylsiloxane (PDMS) materials reported earlier in Sree et al
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Experimental Study of Interface Shearing between Calcareous Sand and Steel Plate Considering Surface Roughness and Particle Size Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-21 Hai-lei Kou; Wen-zhou Diao; Wang-chun Zhang; Jing-bin Zheng; Pengpeng Ni; Bo-An JANG; Chuangzhou Wu
The shear behavior of sand-steel interface plays an important role in the performance of steel pipe piles that support marine structures. In this study, the effects of surface roughness (from rough surface to smooth surface) and mean particle size on mobilized sand-steel interface friction were investigated by direct shear tests. Three types of calcareous sand with different particle sizes and three
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Added resistance using Salvesen–Tuck–Faltinsen strip theory and the Kochin function Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-18 Mostafa Amini-Afshar; Harry B. Bingham
It is now more than half a century since the development of the renowned and well-established strip theory of Salvesen–Tuck–Faltinsen (STF), Salvesen et al.(1970). One of the existing, and widely used, methods for calculating the wave drift force (zero-speed case), or added resistance (forward-speed case), within this strip theory, is a near-field formulation which was developed by Salvesen himself
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Hydraulic Power Take-Off concept for the M4 Wave Energy Converter Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-15 José F. Gaspar; Peter K Stansby; Miguel Calvário; C. Guedes Soares
This paper presents a power take-off concept for the Moored, Multi-float and Multi-Mode Wave Energy Converter, (M4 WEC), based on oil hydraulic technology. The study shows the importance of having low max-to-mean mechanical power ratios, preliminary to the design of the oil-hydraulic power take-off. It explores the characteristics of the M4 WEC in order to achieve these lower power ratios and shows
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Distributed guidance-based formation control of marine vehicles under switching topology Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-16 Cheng Liu; Qizhi Hu; Xuegang Wang
Because of the limited and unreliable communication topology in complex marine environment, the formation control of marine vehicles under switching topology is investigated in this paper, whereas the most previous works for marine formation focused on the fixed communication topology. In order to simplify the formation control design, a novel distributed guidance system, rather than the traditional
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Individual wave overtopping at coastal structures: A critical review and the existing challenges Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-15 Ali Koosheh; Amir Etemad-Shahidi; Nick Cartwright; Rodger Tomlinson; Marcel R.A. van Gent
Conventionally, allowable mean overtopping discharge is used as a design criterion for coastal structures. The mean overtopping discharge needs to be limited to ensure structural stability as well as the safety of people, vehicles, and properties behind the structure. Nowadays, limits for the maximum individual overtopping volumes are also specified in the design manuals, which requires the study of
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Bayesian-based water leakage detection with a novel multisensor fusion method in a deep manned submersible Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-14 Yijun Pan; Zeyu Zheng; Dianzheng Fu
Labeling the observations collected from the deep manned submersible is time-consuming and difficult, and traditional water leakage detection method is supervised. The online and unsupervised water leakage detection methods are necessary but barely researched. In this paper, a multisensor fusion method based on the sparse representation is proposed, and the unsupervised Bayesian-based online diagnostic
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Effects of lateral space and angle of attack on ventilated partial cavity Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-13 Shuai Sun; Shijie Qin; Hezhen Fang; Dazhuan Wu; Bin Huang
Ventilated partial cavity (VPC) is a drag reduction method with great potential for marine vehicles. In applications of VPC ships or yachts, the cavity usually undergoes flow non-uniformity and perturbations induced by hull and pitching motions. This study presents the experimental and numerical investigation on effects of flow non-uniformity and additional pressure gradient on the VPC caused by lateral
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Numerical finite element modelling of soil resistance against upheaval buckling of buried submarine pipelines Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-10 Sahar Ismail; Salah Sadek; Shadi S. Najjar; Mounir Mabsout
Submarine high-temperature and/or high-pressure (HT/HP) pipelines used to transport oil and gas in different areas of the world are susceptible to global buckling. If the pipelines are simply laid on the seabed, buckling will likely occur in the horizontal plane, while if buried in a trench, buckling will probably arise in the vertical direction. The latter buckling mode may lead to catastrophic pipeline
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Fatigue life prediction of ship and offshore structures under wide-banded non-Gaussian random loadings Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-11 Hyeon-jin Kim; Beom-Seon Jang
Ships and offshore structures are exposed to various cyclic loads such as winds, waves and currents in their lifetime. These loads can result in fatigue failures at hot spots, and to prevent such failures, accurate estimates of the fatigue life of hot spots should be performed in the design stage. The cycle distribution indicative of the probability distribution of cycles is an important factor in
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Visual ship tracking via a hybrid kernelized correlation filter and anomaly cleansing framework Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-11 Xinqiang Chen; Xueqian Xu; Yongsheng Yang; Yanguo Huang; Jing Chen; Ying Yan
Ship tracking from maritime visual sensing data (namely maritime surveillance videos) provides various kinematic maritime traffic information, which significantly benefits remote maritime traffic controlling and management, off-site law enforcement, etc. But, it is difficult to extract distinct ship visual features when the target ship is sheltered by the neighboring ship in the maritime images (or
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Controlling a Fishing Net Geometry Underwater Using a Data Assimilation Method Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-10 Shintaro Gomi; Tsutomu Takagi; Katsuya Suzuki; Rika Shiraki; Ichiya Ogino; Shigeru Asaumi
We propose a control method that changes the geometry of a fishing net into an arbitrary geometry. To control the net geometry, an automatic control system was constructed by integrating the data assimilation method into a fishing net dynamics simulation. This study focused on the function of the data assimilation method to estimate the unknown parameter needed to control the net geometry. By applying
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Flow field and drag characteristics of netting of cruciform structures with various sizes of knot structure using CFD models Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-09 Baiqiang Zou; Nyatchouba Nsangue Bruno Thierry; Hao Tang; Liuxiong Xu; Cheng Zhou; Xuefang Wang; Shuchuang Dong; Fuxiang Hu
The knowledge of drag characteristic and flow field around knotless and knotted cruciform patterns is very important for the design of successful netting structures. The effects of ratio between sphere (knot) and cylinder (twine) diameters (D/d) on the surrounding fluid flow and drag of cruciform structures with various attack angles was numerically investigated based on k-ω shear stress turbulent
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A framework for processing wave buoy measurements in the presence of current Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-07 Ajit C. Pillai; Thomas Davey; Samuel Draycott
Waves and currents interact, with the resulting combination largely determining the loading on offshore structures and devices. Despite this, currents are often ignored and wave buoy data is processed without consideration of the current or the wave-current interaction. This data is subsequently used in design, yet sea state power, steepness, and directionality may have significant errors. Here we
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Effects of the position of pipe-type appendages on the flow induced motions, energy transformation, and drag force of a TLP Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-07 Chenling Tian; Mingyue Liu; Longfei Xiao; Rodolfo T. Goncalves; Wenhui Xie; Shisheng Wang
Flow-induced motions (FIM) can cause fatigue damage to the mooring and riser systems of deepwater offshore structures, especially for cylindrical platforms, such as Tension Leg Platform(TLP). Previous experimental and numerical studies have showed conservative FIM prediction compared to the field measurements, due to many significant factors such as the Reynolds number, the nonuniformity of the incident
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Investigation of the manoeuvrability characteristics of a Gate Rudder system using numerical, experimental, and full-scale techniques Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-07 Alessandro Carchen; Serkan Turkmen; Benedetto Piaggio; Weichao Shi; Noriyuki Sasaki; Mehmet Atlar
The Gate Rudder is a recently introduced twin rudder system whose major advantages stem from its energy-saving properties. The two foil-shaped blades of the rudder, placed aside of the propeller, act as a partial duct in the wake of the hull producing additional thrust. However, since the rudder is a primary safety device on any vessel, investigating the manoeuvrability performance of the Gate Rudder
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Numerical analysis of marine propellers low frequency noise during maneuvering Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-06 Giulio Dubbioso; Roberto Muscari; Fabrizio Ortolani; Andrea Di Mascio
In this paper the effects of maneuvering motion on the hydro–acoustic performance of a marine propeller in behind–hull configuration is investigated. Velocities induced by ship motions markedly modify the inflow to the propeller and hence noise sources and emission can be different with respect to the rectilinear motion, that traditionally is exclusively considered during the design process. This problem
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Performance optimization and investigation of flow phenomena on tidal turbine blade airfoil considering cavitation and roughness Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-05 ZhaoCheng Sun; YuFeng Mao; MengHao Fan
Since the underwater impurity and cavitation could have a significant impact on the aerodynamic performance of tidal turbine blade airfoil, it is necessary to consider both roughness and cavitation in the process of optimization design. In the present study, a novel multi-objective evolution algorithm based on NSGA‐II is proposed for the design of tidal turbine blade airfoil, to overcome the adverse
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Nonlinear flow-induced vibration response characteristics of a tubing string in HPHT oil&gas well Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-05 Xiaoqiang Guo; Jun Liu; Guorong Wang; Liming Dai; Dake Fang; Liang Huang; Yufa He
This study has established a nonlinear flow-induced vibration (FIV) model of tubing string by using the micro-element method and energy method with the Hamiltonian variational principle, in order to address the vibration failure problem of the tubing string induced by high-speed fluid flow in the tubing of high temperature and high pressure (HPHT) oil&gas well. This model considered factors such as
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Experimental study on the global behaviour of jack-up unit reinstalled near a footprint Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-04 Ye Yuan; Menglan Duan; Chengliang Zhang; Pan Gao; Xinglan Bai
Spudcan is the foundation of the jack-up unit, and the depression on the seabed left by previous spudcan penetration and extraction was called the footprint. Footprint-spudcan interaction is one of the causal sources of jack-up unit accidents. The depression creates a localized eccentric loading and bending moment on the spudcan and platform legs that invariably cause the tilting of the platform. This
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Theoretical method for generating solitary waves using plunger-type wavemakers and its Smoothed Particle Hydrodynamics validation Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-04 Ming He; Abbas Khayyer; Xifeng Gao; Wanhai Xu; Bijin Liu
Although solitary wave generation using a piston-type wavemaker has been common, the method cannot be applied to all wave tanks because many of them have been or will be equipped with plunger-type wavemakers. How to use a plunger to generate solitary waves as good as those generated by a piston is an unsolved but practically significant problem. Herein, a theoretical method is proposed. New formulae
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A practical INS/GPS/DVL/PS integrated navigation algorithm and its application on Autonomous Underwater Vehicle Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-02 Xiaokai Mu; Bo He; Shuyi Wu; Xin Zhang; Yan Song; Tianhong Yan
The integrated navigation system based on multi-sensor data fusion could effectively improve the navigation accuracy for Autonomous Underwater Vehicle (AUV). Various navigation equipment and sensors have different error characteristics. Current research does not take a specific processor based on their error characteristics, causing the optimal estimation is hard to realize in engineering applications
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Scheduling decision model of liner shipping considering emission control areas regulations Appl. Ocean Res. (IF 2.753) Pub Date : 2020-12-02 Weihao Ma; Shunfeng Hao; Dongfang Ma; Dianhai Wang; Sheng Jin; Fengzhong Qu
Several Emission Control Areas (ECAs) have been established to limit sulfur emissions from ships, thus influencing ship voyage planning. In this study, we used a mixed integer nonlinear programming model (MINLP) to reschedule ports-of-call sequences, ship route, speed, and bunkering strategy to minimize total sailing costs, defined as the sum of bunkering costs, time costs, and carbon emissions costs
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A numerical framework for modelling the dynamics of open ocean aquaculture structures in viscous fluids Appl. Ocean Res. (IF 2.753) Pub Date : 2020-11-29 Tobias Martin; Andrei Tsarau; Hans Bihs
This paper presents a complete numerical framework for modelling open ocean aquaculture structures in waves and current using Computational Fluid Dynamics (CFD). A structural dynamics model is incorporated to account for the motions and deformations of the net. It is based on the lumped mass method, a non-linear material law and implicit time step advancing. The presence of the porous net is considered
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A Finite Volume Based Fully Nonlinear Potential Flow Model for Water Wave Problems Appl. Ocean Res. (IF 2.753) Pub Date : 2020-11-27 Zaibin Lin; Ling Qian; Wei Bai; Zhihua Ma; Hao Chen; Jian-Guo Zhou; Hanbin Gu
A new Fully Nonlinear Potential Flow (FNPF) numerical model has been developed for the simulation of nonlinear water wave problems. At each time step, the mixed boundary value problem for the flow field is spatially discretised by Finite Volume Method (FVM) and the kinematic and dynamic free surface boundary conditions are defined in a semi-Eulerian-Lagrangian form, which are used to update the wave
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Propeller tip vortex mitigation by roughness application Appl. Ocean Res. (IF 2.753) Pub Date : 2020-11-27 Abolfazl Asnaghi; Urban Svennberg; Robert Gustafsson; Rickard E. Bensow
In this study, the application of surface roughness on model and full scale marine propellers in order to mitigate tip vortex cavitation is evaluated. To model the turbulence, SST k−ω model along with a curvature correction is employed to simulate the flow on an appropriate grid resolution for tip vortex propagation, at least 32 cells per vortex diameter according to our previous guidelines. The effect
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Effect of tower elasticity on the performance and fatigue character of monopile support tower for tidal current turbine Appl. Ocean Res. (IF 2.753) Pub Date : 2020-11-26 Sakhi Jan; Saeed Badshah; Mujahid Badshah; Adeel Javed
The design of support structures requires precise knowledge about the effect of support tower on turbine performance, loads and its fatigue character. Therefore, a tidal current turbine mounted on an elastic tubular monopile support tower is simulated in coupled Fluid Structure Interaction (FSI) simulations using ANSYS Workbench. The performance and behavior of turbine loads for an elastic tower is
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