Volume 6A: Ocean Engineering最新文献_第2页

A Review of Mooring Analysis Methodologies for Permanent Offshore Installations 海上永久设施系泊分析方法综述

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18000

S. Pahos, G. Maldonado, P. Westlake

{"title":"A Review of Mooring Analysis Methodologies for Permanent Offshore Installations","authors":"S. Pahos, G. Maldonado, P. Westlake","doi":"10.1115/omae2020-18000","DOIUrl":"https://doi.org/10.1115/omae2020-18000","url":null,"abstract":"\u0000 Traditionally mooring line strength assessment is based on a deterministic approach, where the mooring system is evaluated for a design environment defined by a return period. The mooring system response is then checked against the mooring strength to ensure a required factor of safety. Some codes adopt a deterministic approach [1], [2], [3]. Other codes like [4] adopt a partial safety factor format where uncertainties are addressed through load factors for load components and material factors for line strength. Industry practices give guidance on mooring analysis methodology together with analysis options like coupled, de-coupled, time domain, frequency domain and the associated line tension safety factors. Prior work has demonstrated that discrepancies in mooring line tensions are observed when different analytical approaches are used [5]. Namely, the mooring line tensions of a semi-submersible unit in a coupled time domain analysis, were found to be non-compliant, whereas those calculated using a decoupled time domain analysis returned compliant tensions.\u0000 This work focuses on a coupled dynamic analysis where all inertial, hydrodynamic and mechanical forces are assessed to determine the subsequent motions. Despite being considered the most accurate to capture the true dynamic response, a coupled analysis is also the least efficient in terms of the required computer resources and engineering effort [1].\u0000 This paper presents further discussion on the above observation in mooring tensions and also considers differences in the installation’s excursion. All responses are evaluated in the time domain where the nonlinear dynamic behavior of the mooring lines, slowly varying wave drift forces and coupling effects are captured.\u0000 Agreement is found in the present computations, carried out with two renowned hydrodynamic codes, which validate former results and reiterate the need to distinguish between time domain methods and recommended appropriate safety factors accordingly.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"12 5 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":"133962155","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

Numerical Investigation on Wave Transmission by a Submerged Reef Using MIKE 3 WAVE FM 基于mike3调频的暗礁波传输数值研究

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18499

R. Raju, M. Arockiasamy, R. Sundaravadivelu, Sherlin Prem Nishold Selvaraj

引用次数: 0

Second Order Difference Frequency Wave-Current Loading Using Kelvin-Newman Approximation 利用开尔文-纽曼近似的二阶差频波流加载

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18901

Farid P. Bakti, Moo-Hyun Kim

{"title":"Second Order Difference Frequency Wave-Current Loading Using Kelvin-Newman Approximation","authors":"Farid P. Bakti, Moo-Hyun Kim","doi":"10.1115/omae2020-18901","DOIUrl":"https://doi.org/10.1115/omae2020-18901","url":null,"abstract":"\u0000 Kelvin & Newman introduced a linearization method to include the current (or forward speed) effect into the diffraction & radiation wave field for large-slender floating bodies. The K-N method assumes a steady far-field current while disregarding the steady potential field due to the presence of the body. The method is proven to be reliable when the Froude number is relatively small, the body shape is relatively slender (∂∂x≪∂∂y,∂∂z), and the sea condition is mild. This requirement is fulfilled for typical FPSOs and ship-shaped vessels in a typical current (or forward speed) condition. Several studies suggested that the presence of the current might change the first order hydrodynamic coefficients such as the first order diffraction force, added mass, and radiation damping. Currents also contributed to a change in the second-order slowly-varying drift force. However, the effect of current in the second-order difference-frequency force is yet to be investigated. By expanding the Kelvin-Newman approximation up to the second order, and solving the problem in the frequency domain, we can save computational time while expanding the accuracy of the scheme.\u0000 The second order quadratic force is the main focus of this study, since it is the main contributor to the total second order difference frequency forces especially near the diagonal. By implementing the Kelvin-Newman wave current interaction approach up to the wave’s second order, we can assess the performance of the Kelvin-Newman wave current interaction formulation in various sea conditions.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"35 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":"121223122","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

Numerical Study on the Performance Analysis and Vibration Characteristics of Flexible Marine Propeller 船用柔性螺旋桨性能分析及振动特性数值研究

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18538

K. Ashok, S. Anantha, R. Vijayakumar

{"title":"Numerical Study on the Performance Analysis and Vibration Characteristics of Flexible Marine Propeller","authors":"K. Ashok, S. Anantha, R. Vijayakumar","doi":"10.1115/omae2020-18538","DOIUrl":"https://doi.org/10.1115/omae2020-18538","url":null,"abstract":"\u0000 This paper addresses the hydro-elastic performance of two composite marine propellers at operating condition and compares the results with conventional materials. The study involves three stages namely, design and development of a B series propeller, hydrodynamic and structural performance analysis in uniform flow and free vibration test both in dry and wet condition. In order to perform the hydro-elastic based fluid structure interaction (FSI), Co-Simulation method was adopted to couple Reynolds Averaged Navier-Strokes Equation (RANSE) based Computational Fluid Dynamics (CFD) solver and finite element method (FEM) solvers. The open water characteristics such as thrust coefficient (KT), torque coefficient (KQ), and open water efficiency (ηO) were analyzed as a function of advance velocity (J) of the propeller. A detailed study of the various blade materials by varying mechanical properties are presented. The results obtained show the variation of stress and deflection on the blade, along with the influence of the blade deformation on the performance of propeller. The vibration behaviour of the propellers were also analysed by Block-Lanczos method in FEM solver to obtain the natural frequencies and the mode shapes using Acoustic Fluid-Structure Coupling method for both dry and wet condition. Results showed that composite propeller have better hydro-dynamic property and lower vibration than metal propeller.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"45 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":"123127774","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 New Type of Robot Used for Deep Stratum Drilling in Seabed 一种用于海底深层钻井的新型机器人

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18401

Peihao Zhang, Jia-wang Chen, Tian Zhenwei, Ziqiang Ren, Y. Ge, Gao Qiaoling, F. Gao

引用次数: 1

The Course Control of Air Cushion Vehicle With Uncertainties and Input Saturation 具有不确定性和输入饱和的气垫飞行器航向控制

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-19078

Yuanhui Wang, Jiang Xiyun, Mingyu Fu

{"title":"The Course Control of Air Cushion Vehicle With Uncertainties and Input Saturation","authors":"Yuanhui Wang, Jiang Xiyun, Mingyu Fu","doi":"10.1115/omae2020-19078","DOIUrl":"https://doi.org/10.1115/omae2020-19078","url":null,"abstract":"\u0000 In the presence of input saturation and unknown the internal uncertainties, external disturbances, including sea wind, waves and currents, this paper develops a course control law for the system of air cushion vehicle (ACV) using neural network and auxiliary dynamic system to improve the maneuverability and safety. In the design process of the course control law of air cushion vehicle, the two problems of input saturation and uncertainties are considered. On one hand, an effective auxiliary dynamic system is introduced to solve the input saturation problem and reduce its impact on the system. On the other hand, in order to deal with the internal and external disturbances of the system, the fully turned radial basis function network (FTRBFNN) is combined with the control law, and its adaptive ability makes the system compensate better for unknown uncertainties better than RBFNN. The stability of closed-loop system is proved by Lyapunov analysis. It is proved that the designed course control law can maintain ACV’s heading at desired value, while guaranteeing the uniform ultimate boundedness of all signals in the ACV closed-loop control system. Finally, simulations on ACV are carried out to demonstrate the effectiveness of the developed ACV course control law.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"64 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":"123560001","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

Design, Analysis, and Development of a Wave-Current Laboratory 波浪-电流实验室的设计、分析与开发

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-19253

Nhu-Van Nguyen, Jacob Davis, Ahmed Alshuwaykh, K. Sharman

{"title":"Design, Analysis, and Development of a Wave-Current Laboratory","authors":"Nhu-Van Nguyen, Jacob Davis, Ahmed Alshuwaykh, K. Sharman","doi":"10.1115/omae2020-19253","DOIUrl":"https://doi.org/10.1115/omae2020-19253","url":null,"abstract":"\u0000 In real ocean environments, offshore structures are exposed to a combination of wave and current loading conditions. This scenario presents the need to study fluid-structure interactions in the presence of both conditions, achievable through experimentation in a recirculating flume coupled with a wavemaker. The Ocean Resources and Renewable Energy (ORRE) group set out to design a recirculating wave-current flume at the University of Massachusetts Amherst to enable the study of technologies such as scale floating platforms and marine energy converters. In this paper, we present the methods used to arrive at an optimal flume design under strict spatial constraints posed by the available lab space. Limitations on the length, width, and height of flume are overcome via innovative flow designs and compact structures. The final design is approximately 11.5 m (37.7 ft) in length and 1.2 m (3.9 ft) wide with a nominal water depth of 1 m (3.3 ft). The 2 m long test section begins 6 m beyond the inlet of the flume to maximize flow uniformity. A 24” thruster driven by 75 hp electric motor maintains a current velocity of 0.5 m/s throughout the section while a wedge-shape plunger is implemented at the inlet to generate 0.6–2.8 s period waves with a maximum height of 0.2 m. During the design process, 2D computational fluid dynamics (CFD) simulations are employed to maximize flow uniformity over a range of inlet angles and guide vane configurations. In the optimal scenario, a flow nonuniformity of 8.7 % was obtained across a 0.7 m water column measured from the free surface. Results from the 3D simulation around the tight corner section showed significant increase in flow nonuniformity. The implementation of the screens along the flow path might be necessary in the future.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"45 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":"130091218","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 Effect of Storm-Induced Precipitation on Flooding in Macau City 暴雨降水对澳门市区洪水的影响

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18416

Jie Yang, Jiandong Liu, Dongeon Kim, Linlin Li, K. Mok, P. Liu

{"title":"The Effect of Storm-Induced Precipitation on Flooding in Macau City","authors":"Jie Yang, Jiandong Liu, Dongeon Kim, Linlin Li, K. Mok, P. Liu","doi":"10.1115/omae2020-18416","DOIUrl":"https://doi.org/10.1115/omae2020-18416","url":null,"abstract":"\u0000 The extent and depth of coastal flooding caused by tropical cyclone can be underestimated without considering the contribution by storm-induced precipitation. In this study, the dynamic flooding processes in Macau are simulated accounting for the combined effect of storm surge and precipitation during Typhoon Mangkhut in 2018. The surface wind and atmospheric pressure during this typhoon event are generated by a parametric vortex model and are used to drive a surge–tide–wave model for producing storm-induced water levels. The precipitation rate from ERA5 reanalysis data is utilized in this modelling suite as an additional source of water mass. The numerical model is first thoroughly validated by comparing the numerical results against the measured water levels and significant wave heights at tidal gauge and wave buoy stations. By switching on/off the rainfall function in the mass conservation and momentum equations, we compare and analyze the differences of inundation depths and inundation extent induced by precipitation. The differences in the maximum inundation depths vary spatially and the increments owing to precipitation are less than 50 mm in most flooded regions, the associated contribution is less than 10% in areas with moderate and severe flooding. The effect of precipitation as additional rainfall-induced forces in the momentum equations plays a more important role than that in the mass conservation. The inundation depths induced by tide and surge are approximately two times of that induced by precipitation. Moreover, the compound effects by ocean waves and precipitation tend to decrease the increment of precipitation-induced inundation depths by precipitation alone. Finally, we also assess the performance of the overland flow model Itzï on Macau Peninsula for the same typhoon event. The present study helps identifying vulnerable areas subject to heavy precipitation in Macau and gaining more understanding of flooding mechanisms by different physical drivers.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"418 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":"126020091","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

A Decision Support Framework for Cost-Effective and Energy-Efficient Shipping 成本效益和节能航运的决策支持框架

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18368

Khanh Q. Bui, L. Perera

{"title":"A Decision Support Framework for Cost-Effective and Energy-Efficient Shipping","authors":"Khanh Q. Bui, L. Perera","doi":"10.1115/omae2020-18368","DOIUrl":"https://doi.org/10.1115/omae2020-18368","url":null,"abstract":"\u0000 Stringent regulations regarding environmental protection and energy efficiency (i.e., emission limits regarding NOx, SOx pollutants and the IMO greenhouse gases reduction target) will mark a significant shift to the maritime industry. In the first place, the shipping industry has strived to work towards feasible technologies for regulatory compliance. Nevertheless, life cycle cost appraisal attaches much consideration of decision-makers when it comes to investment decisions on new technologies. Therefore, the life cycle cost analysis (LCCA) is proposed in this study to evaluate the cash flow budgeting and cost performance of the proposed technologies over their life cycles. In the second place, environmental regulations may support innovation especially in the era of digitalization. The industrial digitalization is expected to revolutionize all of the aspects of shipping and enable the achievement of energy-efficient and environmental-friendly maritime operations. The so-called Internet of things (IoT) with the utilization of sensor technologies as well as data acquisition systems can facilitate the respective maritime operations by means of vessel operational performance monitoring. The big data sets obtained from IoT should be properly analyzed with the help of Artificial Intelligence (AI) and Machine Learning (ML) approaches. Our contribution in this paper is to propose a decision support framework, which comprises the LCCA analysis and advanced data analytics for ship performance monitoring, will play a pivotal role for decision-making processes towards cost-effective and energy-efficient shipping.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"6 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":"133238283","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

Time-Domain Simulation of Subsea Equipments Installation Using Hydrodynamic Derivatives 基于水动力导数的水下设备安装时域仿真

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18311

Emerson Martins de Andrade, J. S. Sales, A. C. Fernandes, M. Ribeiro, P. Teixeira

{"title":"Time-Domain Simulation of Subsea Equipments Installation Using Hydrodynamic Derivatives","authors":"Emerson Martins de Andrade, J. S. Sales, A. C. Fernandes, M. Ribeiro, P. Teixeira","doi":"10.1115/omae2020-18311","DOIUrl":"https://doi.org/10.1115/omae2020-18311","url":null,"abstract":"\u0000 The installation of a subsea equipment such as manifold needs careful planning and coordination. Studies on the behavior of the dynamic responses are crucial to guarantee safety.\u0000 Some important factors in these operations include the current profile, waves characteristics, winches motions at topside, and the elastic behavior of the cable (due to resonance effects).\u0000 Currently, most of the available commercial codes use simplified models for the hydrodynamic forces of submerged equipment. However, for cases with complex geometries and strong interactions with the environmental loads, those models fail to represent correctly the dynamics.\u0000 In this paper we present an initial method and a hydrodynamic model to include terms that allow the modelling of complex behavior of submerged complex geometries by using hydrodynamic derivatives extracted from model tests. To verify the procedure, tests were performed both at a flume tank and at a towing tank. The model was implemented in a commercial code by using a Simplified Buoy model, to which a python procedure that calculated the hydrodynamic forces was attached. The study was divided into two phases: the first one consisted of the verification of the effectiveness of the external routine. This was done for a manifold in 1DOF and then in 6 DOF. In the second phase, the dynamic maneuvering model using Hydrodynamic Derivatives was implemented as an external routine and, using the output from dynamic excitation experiments at small scale with a manifold, kinematical behavior results were compared.\u0000 Results showed good adherence, although some further investigations are still needed.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"59 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":"123396486","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