Volume 6A: Ocean Engineering最新文献

Towing Experiment of a Hydro-Structural Container Ship Model in Bow-Quartering Modulated Wave Trains 船首四分位调制波列中水工结构集装箱船模型拖曳试验

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18272

H. Houtani, Yusuke Komoriyama, S. Matsui, M. Oka, H. Sawada, Yoshiteru Tanaka, T. Waseda

{"title":"Towing Experiment of a Hydro-Structural Container Ship Model in Bow-Quartering Modulated Wave Trains","authors":"H. Houtani, Yusuke Komoriyama, S. Matsui, M. Oka, H. Sawada, Yoshiteru Tanaka, T. Waseda","doi":"10.1115/omae2020-18272","DOIUrl":"https://doi.org/10.1115/omae2020-18272","url":null,"abstract":"\u0000 We experimentally investigated the influence of the geometries of a modulated wave train on the vertical-bending and torsional moments acting on a container ship in bow-quartering sea conditions. We conducted a towing experiment with a hydro-structural container ship model in the Actual Sea Model Basin (ASMB) (80 m deep, 40 m wide, and 4.5 m deep) at the National Maritime Research Institute. The ship model is made of urethane foam and was designed to have similar vertical bending and torsional vibration mode shapes to an actual ship. A modulated wave train was generated in the ASMB by the higher-order spectral-method wave generation (HOSM-WG) method such that the maxim crest appeared at the center of the basin. The ship model was towed in the modulated wave train with a relative heading angle of 120 degrees. A series of tests was performed by varying the encounter timing of the ship model and the maximum crest of the modulated wave train. In the experiment, fiber-Bragg-grating strain gauges successfully measured whipping vibrations of the ship model due to a slamming impact. The experimental results revealed that the rear wave height Hr and the ratio of the rear and front wave heights Hr/Hf were the dominant parameters governing the maximum sagging and torsional moments of a ship in bow-quartering modulated wave trains.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"165 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":"116140390","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 Invertigation of Water Entry of a Subsea Module With Deflated Cavity Shells 带放气腔壳的水下模组进水数值研究

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-19118

Yingfei Zan, Guo Ruinan, Lihao Yuan, F. Huang, Dongchun Kang

{"title":"Numerical Invertigation of Water Entry of a Subsea Module With Deflated Cavity Shells","authors":"Yingfei Zan, Guo Ruinan, Lihao Yuan, F. Huang, Dongchun Kang","doi":"10.1115/omae2020-19118","DOIUrl":"https://doi.org/10.1115/omae2020-19118","url":null,"abstract":"\u0000 In subsea installation operations, the hydrodynamic forces on the subsea module are important considerations when designing the structure and choosing slings. In this paper, the hydrodynamic forces and flow field of a subsea module with deflated cavity shells during forced water entry operation were investigated numerically. The numerical simulation was carried out based on Reynolds-averaged Navier–Stokes equations, with a constant lowering velocity of the module. The results of the numerical simulation were validated by experimental data and they showed good agreement. The relationship between hydrodynamic forces and draft was presented. Furthermore, the slamming positions, free surface variation, pressure variation in deflated cavity shells, slamming coefficient and the influence of holes were studied based on flow field scenes. It was found that the hydrodynamic forces varied with draft non-linearly. Moreover, the change of draft altered the form of the free surface due to the complex steel frame structure of deflated cavity shells. The present study can be further extended to assess the operating conditions of lifting operations and to advise on the design of the subsea module.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"352 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":"115893709","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

Stinger Structural Analysis Using Fully Coupled Model for Pipelay Operations 基于全耦合模型的管道管柱结构分析

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18862

Anupam Gupta, S. Tallavajhula, Sachin Mathakari

{"title":"Stinger Structural Analysis Using Fully Coupled Model for Pipelay Operations","authors":"Anupam Gupta, S. Tallavajhula, Sachin Mathakari","doi":"10.1115/omae2020-18862","DOIUrl":"https://doi.org/10.1115/omae2020-18862","url":null,"abstract":"\u0000 With the growing demands and increasing challenges in deep-water pipeline installation, it is increasingly important to optimize stinger capacity assessment procedure for higher level of accuracy and cost-efficiency as compared to the traditional approach which is highly conservative.\u0000 The traditional approach combines maximum stresses from three different analyses for environmental loads, vessel motions and pipeline forces to calculate the dynamic performance of a stinger. This approach ignores the coupled behavior between stinger, vessel and pipeline leading to conservative results and over-design which significantly underestimates the operational limits of the stinger structure.\u0000 The main objective of this study is to develop a simple yet optimized and accurate stinger design and analysis procedure by considering the combined effect of vessel motion, pipeline forces and environmental loading on stinger structure. This is achieved by performing a Fully Coupled Analysis (FCA) in time domain, with capability to capture the impact of stiffness and hydro-elastic properties of stinger and pipeline. The fully coupled model also allows inclusion of hydrodynamic loads on installation vessel as compared to use of vessel motion RAOs in the traditional approach. Forces from this time-history analysis are extracted and mapped onto the structural model to check for structural strength using API and AISC codes.\u0000 This paper presents a comparison between structural analysis results obtained from Fully Coupled Analysis (FCA) and traditional approach. Results from the FCA procedure have shown significant improvement in the operational limits of stinger.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"146 2 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":"126255059","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

HSE Consequences of FPSO Mooring Lines Pretension Uncertainty in Deep Waters Applications 深水应用中FPSO系泊索预张力不确定性对HSE的影响

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-19291

J. B. Araujo, J. S. Sales, A. C. Fernandes, Ana Clara Thurler

{"title":"HSE Consequences of FPSO Mooring Lines Pretension Uncertainty in Deep Waters Applications","authors":"J. B. Araujo, J. S. Sales, A. C. Fernandes, Ana Clara Thurler","doi":"10.1115/omae2020-19291","DOIUrl":"https://doi.org/10.1115/omae2020-19291","url":null,"abstract":"\u0000 The purpose of FPSO (Floating Production Storage and Offloading) mooring system is to keep the unit operating in site in order to attend the Health, Safety and Environment (HSE) requirements and to meet the production risers design requirements. The pretension specification is a design task and it is a key activity due to its influence on extreme loads and fatigue life for both the mooring lines and risers. It is surprising that the project pretension specifications are not always actually implemented in practice and followed during all the unit life. Some inaccurate methods are used to get the actual pretension and may cause significant errors, and this may cause pretensions values outside design allowable tolerances.\u0000 A contemporary uncertainty analysis method that uses numerical simulations to estimate the consequences and propagation of the uncertainties in pretensions is applied. A case study is presented for the case of an operating FPSO moored by a spread system, offshore Brazil. A second investigation compares the uncertainty of pretensions measured by means of sensors with the uncertainties that arise from indirect measurements by top angles and as built data for mooring segments and anchor points.\u0000 The paper finally shows the need of a Mooring Integrity Management (MIM) implementation of at least annual pretension measurements with a robust and higher precision system.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"28 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114032693","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 New Type of Device Used on Submarine Landslides Monitoring 一种用于海底滑坡监测的新型装置

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18302

Y. Ge, Jia-wang Chen, C. Cao, Gao Qiaoling, Peihao Zhang, Jiamin He

引用次数: 2

Experimental Study of Slam Forces on External Turrets With Different Top Angles 不同顶角外炮塔撞击力的实验研究

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18327

Yukihiro Ishihara, M. Murai, So Nakanishi, S. Kato, Y. Nakajima

{"title":"Experimental Study of Slam Forces on External Turrets With Different Top Angles","authors":"Yukihiro Ishihara, M. Murai, So Nakanishi, S. Kato, Y. Nakajima","doi":"10.1115/omae2020-18327","DOIUrl":"https://doi.org/10.1115/omae2020-18327","url":null,"abstract":"\u0000 The external turret is widely used for mooring FPSOs. However, external turrets can be exposed to slamming and it leads to generate FPSO’s whipping. To analyze the fatigue strength of the FPSOs, probability distributions of slam forces acting when slamming happens are necessary. In this study, we focus on slam force filtered by 10Hz low-pass filter. Then, we examined the probability distribution of peak slam forces, the effect of the top angle on slam forces, and the difference of two types (fixed and oscillator-mounted) tests. For three turret models with different top angle (180°, 160°, and 140°), two types of model tests were carried out.\u0000 To confirm the experiment’s validity and reliability, we compared these model tests with the previous study. The slam forces measured on a conical (140°) turret were consistent with the estimated curve in the previous study. The comparison of two types of tests indicated that fixed turret tests were an easy and valid way of measuring the slam forces on external turrets.\u0000 3-hour return values calculated by five methods were used to examine the characteristic of each turret. And these values were compared with 3-hour mean maxima to examine the difference between the five methods and experimental results. As a result, the use of Generalized Extreme Values and Generalized Pareto distributions is more suitable than using Rayleigh distribution in estimating return values of slam forces on external turrets.","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":"131342131","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

An Optimization Method for Economical Ship-Routing and Ship Operation Considering the Effect of Wind-Assisted Rotors 考虑风助转子影响的船舶经济航路和船舶运行优化方法

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18776

Wen-Juan Sun, Liu Xiyang, Li Yang

{"title":"An Optimization Method for Economical Ship-Routing and Ship Operation Considering the Effect of Wind-Assisted Rotors","authors":"Wen-Juan Sun, Liu Xiyang, Li Yang","doi":"10.1115/omae2020-18776","DOIUrl":"https://doi.org/10.1115/omae2020-18776","url":null,"abstract":"\u0000 With the increasingly strict regulations for energy saving and emission reduction technology of ships, minimizing fuel cost is one of the most critical issues in the design and operation of merchant ships. A method to reduce the fuel cost for merchant ship is to select an economical route based on the real-time meteorological environment and weather forecasting data. So far, numerous ship routing strategies have been proposed with the development of weather routing system. More recently, many wind-assisted devices like rotors, wind sails, etc. have been investigated and designed to utilize the renewable wind energy. With the equipment of wind-assisted rotors, the optimization of ship route becomes more important because the effect of this wind-assisted device highly depends on the local wind field along the ship route. In this paper, an improved optimization strategy with the combination of the A* algorithm and a realtime optimizer has been proposed to determinate the optimal ship route and ship operations including ship heading, propeller’s rpm and rotor’s rpm. The real-time information for the weather conditions, ocean climate and sea states are obtained from European Center for Medium-range Weather Forecasts and the ship performance is evaluated by data-driven models. Finally, the proposed method was applied to test cases of ships operating in Pacific route and Indian Ocean route and the results show that the total fuel consumption could be reduced compared to the minimum distance route.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"21 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":"127184039","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

Experimental Study on the Behavior of a Bubble in the Vicinity of an Air Bubble Attached to a Fixed Structure 附在固定结构上的气泡附近气泡行为的实验研究

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18144

Jia-xia Wang, Kun Liu

{"title":"Experimental Study on the Behavior of a Bubble in the Vicinity of an Air Bubble Attached to a Fixed Structure","authors":"Jia-xia Wang, Kun Liu","doi":"10.1115/omae2020-18144","DOIUrl":"https://doi.org/10.1115/omae2020-18144","url":null,"abstract":"\u0000 The interaction between a spark-generated bubble and a non-oscillating air bubble attached to a horizontal rigid plate is investigated using a low-voltage spark-discharge setup. Large numbers of fascinating and complicated interactions are given rise during two bubble coupling pulsation due to the deformation property endowed to the plate through an air bubble attached. It is found that, under the combined influence of the cavitation and the structure, some complex phenomenon likes the bubble coalescence, air bubble skirt phenomenon, bubble splitting are given rise during the two bubble interaction procedure. The coupling phenomenon between the spark generated bubble, air bubble and the structure are discussed in detailed The mainly attention are paid to the coupled response of an attached quiescent bubble under oscillating bubble, the effect of the distance parameter and volume ratio parameter on the air bubble shapes are analyzed in detail, and the mechanism behind these phenomenon are investigated. Our study can be a useful scheme in the protection of a naval structure from threats induced by an explosion bubble impact loading.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"224 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":"128431249","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

Research on Intelligent Loading of Bulk Carriers 散货船智能装载技术研究

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18209

Sheng Fang, Shunhuai Chen

{"title":"Research on Intelligent Loading of Bulk Carriers","authors":"Sheng Fang, Shunhuai Chen","doi":"10.1115/omae2020-18209","DOIUrl":"https://doi.org/10.1115/omae2020-18209","url":null,"abstract":"\u0000 With the rapid development of computer technology in recent years, the shipbuilding industry is accelerating its intelligent process. Intelligent cargo management is an important functional module of intelligent ships, and intelligent loading is an important part of intelligent cargo management. Cargo loading is an important link in the process of cargo transportation. The loading effect affects the sailing performance, safety performance and loading efficiency of the ship, so it is necessary to improve the intelligence of ship loading. Based on the calculation and research of the floating state, stability, structural strength and loading efficiency of the bulk carrier during loading, a general mathematical model for the intelligent loading of bulk carriers is established. The model comprehensively considers the influence of loading rounds, loading capacity and loading order. It is solved using an improved genetic algorithm to obtain optimized loading results. The loading case calculation was carried out using a 20000t bulk carrier as an example, and an optimized solution was obtained, which proved the effectiveness of the algorithm. The results show that the method can effectively improve the loading efficiency of the ship while ensuring that the ship has sufficient strength and suitable floating state.","PeriodicalId":427872,"journal":{"name":"Volume 6A: Ocean Engineering","volume":"16 2 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":"132268580","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

Vessel/Stinger/Pipeline Fully Coupled Analysis for Pipelaying Operation 管道作业的容器/推力杆/管道全耦合分析

Volume 6A: Ocean Engineering Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18857

Bonjun Koo, Qin Tu, Jiaqi Wang, Sachin Mathakari

引用次数: 0