Volume 6A: Ocean Engineering最新文献_第4页

Study on the Architecture of a Zero Emission Hydrogen Fuel Cell Vessel Power Generating Unit 零排放氢燃料电池船舶发电机组结构研究

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18093

Lorenzo Balestra, I. Schjølberg

{"title":"Study on the Architecture of a Zero Emission Hydrogen Fuel Cell Vessel Power Generating Unit","authors":"Lorenzo Balestra, I. Schjølberg","doi":"10.1115/omae2020-18093","DOIUrl":"https://doi.org/10.1115/omae2020-18093","url":null,"abstract":"\u0000 This study focuses on providing design guidelines for a vessel’s power-plant in the multi-megawatt range, equipped with a hybrid fuel cell and battery system. Background information is provided on the challenges to realizing such a system, spanning from a literature review on studies looking into energy management, to the technical limitations of state-of-the-art fuel cells and batteries. The central part of the work consists of the description of the model used to calculate the size of the hybrid power generating unit, including a case study on a single, real-world scenario. The Plant Analysis Balance with Operational Profile (PABOP) model, developed by the author and presented in the paper, is used to calculate the resources needed to retrofit a vessel operating on fossil fuels with a hybrid zero-emission power-plant. The model aim is to achieve a 1:1 replacement for diesel-electric configurations, both in terms of range and power, using fuel cell and battery power. In the case study, the model is applied to analyze the operational data of a double-ended ferry operating with diesel-electric propulsion. Emphasis is put on the I/O needed and produced by the model, and how this tool can be used by shipyard engineers to estimate the footprint required, the necessary storage capacity, lifetime of components and other parameters. The presented solutions could help manufacturers estimate the economical viability of hydrogen vessels, filling a gap in current maritime fleets where zero-emission systems are gaining increasing importance.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"66 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":"125897277","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

An Optimized Thrust Allocation Algorithm for Dynamic Positioning System Based on RBF Neural Network 基于RBF神经网络的动力定位系统推力优化分配算法

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18267

Tang Ziying, Lei Wang, Fan Yi, Huacheng He

{"title":"An Optimized Thrust Allocation Algorithm for Dynamic Positioning System Based on RBF Neural Network","authors":"Tang Ziying, Lei Wang, Fan Yi, Huacheng He","doi":"10.1115/omae2020-18267","DOIUrl":"https://doi.org/10.1115/omae2020-18267","url":null,"abstract":"\u0000 The thrust allocation of Dynamic Positioning System (DPS) equipped with multiple thrusters is usually formulated as an optimization problem. Hydrodynamic interaction effects such as thruster-thruster interaction results in thrust loss. This interaction is generally avoided by defining forbidden zones for some azimuth angles. However, it leads to a higher power consumption and stuck thrust angles. For the purpose of improving the traditional Forbidden Zone (FZ) method, this paper proposes an optimized thrust allocation algorithm based on Radial Basis Function (RBF) neural network and Sequential Quadratic Programming (SQP) algorithm, named RBF-SQP. The thrust coefficient is introduced to express the thrust loss which is then incorporated into the mathematical model to remove forbidden zones. Specifically, the RBF neural network is constructed to approximate the thrust efficiency function, and the SQP algorithm is selected to solve the nonlinear optimization problem. The training dataset of RBF neural network is obtained from the model test of thrust-thrust interaction. Numerical simulations for the dynamic positioning of a semi-submersible platform are conducted under typical operating conditions. The simulation results demonstrate that the demanded forces can be correctly distributed among available thrusters. Compared with the traditional methods, the proposed thrust allocation algorithm can achieve a lower power consumption. Moreover, the advantages of considering hydrodynamic interaction effects and utilizing a neural network for function fitting are also highlighted, indicating a practical application prospect of the optimized algorithm.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"32 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":"116587591","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

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