Volume 6A: Ocean Engineering最新文献_第4页

Experiment-Scale Multi-Vessel Dynamic Positioning System for the Twin-Lift Decommissioning Operation 实验规模双升力退役作业多船动态定位系统

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18631

Z. Fu, Wei Li, Hao Sun, Meng Yuan, Xin Li, Liancai Cai, Andy Wang, Xiaoxian Guo, Handi Wei, Xinliang Tian

{"title":"Experiment-Scale Multi-Vessel Dynamic Positioning System for the Twin-Lift Decommissioning Operation","authors":"Z. Fu, Wei Li, Hao Sun, Meng Yuan, Xin Li, Liancai Cai, Andy Wang, Xiaoxian Guo, Handi Wei, Xinliang Tian","doi":"10.1115/omae2020-18631","DOIUrl":"https://doi.org/10.1115/omae2020-18631","url":null,"abstract":"\u0000 In general, the lifetime of the offshore oil and gas platform is about 20–30 years, and a large number of oil and gas platforms is approaching the end of their service. So, how to decommission these oil and gas platforms safely and cleanly becomes an urgent problem for the oil and gas industry and related organizations. And the costs for decommissioning equipment and services are expected to be as low as possible. It is important to develop the innovative removal techniques to reduce the overall cost of decommissioning. In this paper, we propose a new concept to remove large and heavy structures with a single lift, utilizing three semi-submerged vessels. The main process of the twin-lift solution for decommissioning includes two semi-submerged vessels lifting the topside together, and then carrying the topside to the third semi-submerged vessel. This method is simple in principle and does not require the manufacture of new special vessels, only needs to make simple modifications to existing semi-submerged vessels. It requires high positioning accuracy especially under environmental disturbances to ensure the safety of transportation. To ensure efficiency and safety, we develop a dynamic positioning (DP) system and perform a wave tank test for such a twin-lift decommissioning solution. Some aspects of an experimental facility set-up for scaled model test with dynamic positioning system are described. It includes the topology of the experiment and details of the deck mating, DP and monitoring system.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124090086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

A Modelling System for Power Consumption of Marine Traffic 海上交通动力消耗建模系统

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18651

H. A. Tvete, B. Guo, Qin Liang, H. Brinks

{"title":"A Modelling System for Power Consumption of Marine Traffic","authors":"H. A. Tvete, B. Guo, Qin Liang, H. Brinks","doi":"10.1115/omae2020-18651","DOIUrl":"https://doi.org/10.1115/omae2020-18651","url":null,"abstract":"\u0000 The International Maritime Organization (IMO) has enforced stricter limit on the Greenhouse Gas (GHG) emission due to environment and climate concern. The measures to reduce GHG emissions from shipping can be divided into two groups. The first one is to improve ship energy efficiency through new technology, optimized operation and logistics, and the second one is to introduce alternative fuels with lower carbon intensity. However, the effectiveness and applicability of any measure depend on ship type, ship size, operation type, operation environment (wind and wave condition), as well as the cost of the measure. It is necessary to evaluate new measures in real shipping scenario. Modeling of ship fuel consumption and emission are fundamental input to evaluate the impacts of shipping on the environment and climate, and to evaluate new measures for reducing GHG emission. A modeling system is developed to estimate ship fuel consumption and emission, based on ship hydrodynamical models, information from Automatic Identification System (AIS), the IHS Fairplay database and metocean data. The modeling system aims to cover most of the ship types equipped with AIS transponders, and it will provide different hydrodynamical models to calculate fuel consumption based on the available ship information. In the paper, the modeling system will be described, and the power consumption from the modeling system are compared with the measurement data on one container ship. The comparison shows that the power consumption predicted with the modeling system agrees with measurement data well. The effects of weather data and measured speed on predicted power consumption are also analyzed.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124337022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Numerical Investigation of Scour Beneath a Subsea Piggyback Pipeline 海底管线冲刷数值研究

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18789

Jun Huang, G. Yin, M. Ong, Xu Jia

引用次数: 0

Design and CFD Self-Propulsion Analysis of a Ducted Propeller for a DARPA SUBOFF Hull Autonomous Underwater Vehicle DARPA SUBOFF船体自主水下航行器导管螺旋桨设计及CFD自推进分析

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18226

R. Sbragio, Alceu Moura, R. C. D. Silva

{"title":"Design and CFD Self-Propulsion Analysis of a Ducted Propeller for a DARPA SUBOFF Hull Autonomous Underwater Vehicle","authors":"R. Sbragio, Alceu Moura, R. C. D. Silva","doi":"10.1115/omae2020-18226","DOIUrl":"https://doi.org/10.1115/omae2020-18226","url":null,"abstract":"\u0000 This paper presents the design and the CFD self-propulsion analysis of a ducted propeller to operate in a DARPA SUBOFF hull Autonomous Underwater Vehicle (AUV). The ducted propeller is of the pump jet type with 9 blades at the rotor and 11 blades at the stator. The interactive process of design and optimization uses the potential lifting line theory and CFD RANS analysis for obtaining the self-propulsion point, with the propeller placed behind the AUV hull. During the lifting line design, the rotor diameter, hub diameter, design rotation, blade section chord and length of the duct are modeled by a Kriging Metamodel technique and optimized through random sampling in order to maximize the quasi propulsive coefficient. The optimized configuration from the lifting line and Kriging Metamodel is analyzed using Ansys Fluent 2019 solver. The CFD analysis behind the hull allows including wake effects, thrust deduction factor and viscous effects directly into the model. The lifting line and CFD processes are used interactively to optimize the pitch, the circulation and the camber until the required thrust is achieved.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"368 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122050252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Study on 2nd-Order Wave Loads With Forward Speed Through Aranha’s Formula and Neumann-Kelvin Linearization 用Aranha公式和Neumann-Kelvin线性化研究具有正向速度的二阶波载荷

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18137

Zhitian Xie, Jeffery Falzarano

{"title":"Study on 2nd-Order Wave Loads With Forward Speed Through Aranha’s Formula and Neumann-Kelvin Linearization","authors":"Zhitian Xie, Jeffery Falzarano","doi":"10.1115/omae2020-18137","DOIUrl":"https://doi.org/10.1115/omae2020-18137","url":null,"abstract":"\u0000 The 2nd-order wave loads consist of difference frequency, sum frequency components and a steady drift component that is also called the mean drift load. The first two components are usually not of interest, because of their small amplitudes compared with the 1st-order wave loads. The remaining mean drift load should be taken into consideration due to its steady effect on floating bodies. In the previous research, the full derivation and expression of the 2nd-order wave loads applied to a floating structure was presented. Moreover, numerically estimated quadratic transfer function was also illustrated with both off-diagonal elements and diagonal elements called the mean drift coefficients. Most research topics in this scenario consider the wave only case. In this paper, the mean drift wave loads applied to a floating structure with forward speed or current velocity has been numerically estimated through Aranha’s formula, a far field method and Neumann-Kelvin linearization, a near field method. Therefore, the effect of the floating structure’s forward speed or current velocity on the 2nd-order mean drift loads that is also called the wave drift damping has been discussed through these two methods. This work will provide a meaningful reference and numerical basis for the ongoing projects of the floating structure’s seakeeping and maneuvering problems.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132545025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Unsupervised Trajectory Anomaly Detection for Situation Awareness in Maritime Navigation 面向海上导航态势感知的无监督轨迹异常检测

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18281

B. Murray, L. Perera

引用次数: 2

Capturing Wake Stiffness in Wake-Induced Vibration of Tandem Cylinders 串联式气缸尾迹诱导振动中尾迹刚度的捕获

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18423

Bruno Soares, N. Srinil

{"title":"Capturing Wake Stiffness in Wake-Induced Vibration of Tandem Cylinders","authors":"Bruno Soares, N. Srinil","doi":"10.1115/omae2020-18423","DOIUrl":"https://doi.org/10.1115/omae2020-18423","url":null,"abstract":"\u0000 When a downstream circular cylinder is in the vicinity of the disturbed wake flow which is originated from the presence of an upstream cylinder, fluid-structure interactions due to vortex- and wake-induced vibrations may coexist. Their combined effects are of practical concern for offshore structures deployed in an array or proximity such as marine risers, pipelines and mooring lines. The wake flow deficit law and wake-induced drag and lift hydrodynamic forces are modelled based on the boundary layer theory, which is modified to account for the oscillation of the upstream cylinder. Unsteady drag and lift forces associated with the vortex-induced vibration (VIV) and wake-induced vibration (WIV) are represented dynamically by van der Pol-type wake oscillators. The present paper proposes a new modelling concept and framework capable of evaluating the combined WIV-VIV of tandem circular cylinders in comparison with experimental data, capturing a key feature of the wake stiffness associated with WIV. An equivalent natural frequency based on the wake stiffness mechanism behaves equivalently to the WIV frequency. Numerical studies show that the downstream cylinder may respond in a multi-frequency scenario at specific reduced velocities. The prediction model captures the wake stiffness trend similar to the experimental observation. The correlation to the wake stiffness concept allows the identification of situations for which the downstream cylinder is mainly governed by the WIV mechanism resulting in largest vibration amplitudes.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122502393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hydrodynamic Analysis of Floating Docks With Alternative Geometries for Floating Wind Turbine Installation 浮动式风力发电机具用不同几何形状浮船坞的水动力分析

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18756

Viktor A. Gran, Zhiyu Jiang, Z. Pan

{"title":"Hydrodynamic Analysis of Floating Docks With Alternative Geometries for Floating Wind Turbine Installation","authors":"Viktor A. Gran, Zhiyu Jiang, Z. Pan","doi":"10.1115/omae2020-18756","DOIUrl":"https://doi.org/10.1115/omae2020-18756","url":null,"abstract":"\u0000 Installation of spar floating wind turbine offshore is a challenging task. Usually, the spar platform is upended first, and mating of the tower assembly with the spar platform is assisted by a crane vessel. Due to motions of the spar platforms and of the crane vessel, such an operation often takes place in shielded areas with relatively small wave heights and wind speed. The floating dock concept has been recently proposed to expand the weather window for installing spar floating wind turbines. The idea is to use a cylindrical dock to shield the spar platform from wave excitations. However, because of the trapped internal fluid, the cylindrical geometry is subjected to piston mode and sloshing mode excitations, and these modes may fall in the wave periods and cause unfavourable response characteristics. This paper investigates the influence of floating dock geometries on the piston and sloshing modes. We assumed a homogeneous mass distribution of the floating dock and changed the geometry of the cylindrical dock by expanding or reducing the neck area. Then, hydrodynamic analysis of the alternative geometries was carried out using a potential flow code. By comparing the system’s piston modes and sloshing modes, we identified the trend of variation and found that an expanded neck area can lead to increased sloshing period and piston mode. This indicates a potential improvement of the dock responses in operating sea states. The results of this analysis can be used in the shape design optimisation in a future work.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116410462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Effects of Hydrodynamic Forces on Maneuvrability Coefficients for Wind-Assisted Ships 水动力对风助船舶机动系数的影响

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18673

L. M. Giovannetti, F. Olsson, M. Alexandersson, S. Werner, C. Finnsgård

{"title":"The Effects of Hydrodynamic Forces on Maneuvrability Coefficients for Wind-Assisted Ships","authors":"L. M. Giovannetti, F. Olsson, M. Alexandersson, S. Werner, C. Finnsgård","doi":"10.1115/omae2020-18673","DOIUrl":"https://doi.org/10.1115/omae2020-18673","url":null,"abstract":"\u0000 Assessing the manoeuvring performances of a ship at a design stage is becoming more important, especially when trying to improve shipping efficiency to reduce fuel consumption.\u0000 When designing a hull with appendages, it is necessary to balance hydrodynamic efficiency with manoeuvrability. Therefore, the possibility of simulating a captive test at a design stage will increase the chances of understanding the behaviour of a ship from an early stage in the design process. The current research is based on the evaluation of hydrodynamic efficiency of a hull and appendages in a pure resistance, self-propulsion and in a wind-assisted mode.\u0000 The forces and moments acting on the hull and appendages are then analysed and used as inputs for a Virtual Captive Test (VCT) [1]. In order to correctly perform a VCT and further analyse the performances of a ship with a Velocity Prediction Programme (VPP), particular care has been put in correctly capturing the manoeuvrability coefficients. Those are derived with polynomial fittings once the forces and moments acting on the ship are extracted from the Computational Fluid Dynamics (CFD) simulations.\u0000 Many CFD simulations were performed to assess the hydrodynamic characteristics of the hull and appendages in a range of flow directions, rudder angles and rotating flow. Those simulations encompass the whole range of datapoints needed to describe a wind-assisted ship during manoeuvring.\u0000 Taking into consideration both hydrodynamic characteristics and manoeuvrability effects at an early design stage can reduce model tests costs and will allow to inspect a larger number of hull-appendages scenarios when analysing the final VPP results.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129842683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Effect of a Passive Tuned Mass Damper on Offshore Installation of a Wind Turbine Nacelle 被动调谐质量阻尼器对风力机机舱海上安装的影响

Volume 6A: Ocean Engineering Pub Date : 2020-07-01 DOI: 10.1115/omae2020-18171

Zhiyu Jiang, Trond Skrudland, M. Karimirad, Constatine Machiladies, W. Shi

{"title":"Effect of a Passive Tuned Mass Damper on Offshore Installation of a Wind Turbine Nacelle","authors":"Zhiyu Jiang, Trond Skrudland, M. Karimirad, Constatine Machiladies, W. Shi","doi":"10.1115/omae2020-18171","DOIUrl":"https://doi.org/10.1115/omae2020-18171","url":null,"abstract":"\u0000 Although the installation of offshore wind turbines takes place in calm seas, successful mating of wind turbine components can be challenging due to the relative motions between the two mating parts. This work investigates the effect of a passive tuned mass damper on the mating processes of a nacelle for a 10-megawatt (MW) offshore wind turbine. A nacelle with lifting wires and a monopile with a mass damper are respectively modelled using the multibody formulation in the HAWC2 program. A single mass damper is tuned to target at the first natural period of the monopile and is coupled to the main program using a dynamic link library. Afterwards, numerical simulations were carried out in turbulent wind conditions and irregular wave conditions typical of offshore installation scenarios. Important response variables including the tower-top motions, nacelle motions, and their relative motions are examined in the analysis. By comparing the time series and response statistics, we found that the tower-top motion is more crucial to the installation process than the lifted nacelle motion. For the relative motions and velocities between the nacelle and the tower top, the tuned mass damper can reduce the short-term maximum values by more than 50% for the examined sea states with spectral period between 4 to 12 seconds. This implies that the weather window for marine operations can be expanded if the tuned mass damper is applied.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131833059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2