多学科设计优化算法比较及其在船舶和海洋平台设计上的应用

多学科设计优化(Multidiseiplinary Design Optimization,简称MDO)是一种通过充分探索和利用系统中的相互作用的协同机制来设计复杂系统工程和子系统的方法论.多学科设计优化算法是其核心部分,也是研究最活跃的领域.文中首先介绍了MDO算法的定义、分类和发展,然后从算法的来源和目的、优化过程、优缺点、改进方法和应用情况等五个方面对四种基于分解技术的MDO算法进行了综述,进而对比了这四种算法的异同点.最后,针对船舶和海洋平台设计的具体特点,归纳了适合于船舶或海洋平台多学科设计优化的MDO算法所需要具备的特征,并建议使用基于近似模型的协同优化算法或BUSS 2000算法进行船舶和海洋平台的多学科设计优化.     

浮式海上风力机运动性能和锚泊系统(英文)

The development of offshore wind farms was originally carried out in shallow water areas with fixed(seabed mounted) structures.However,countries with limited shallow water areas require innovative floating platforms to deploy wind turbines offshore in order to harness wind energy to generate electricity in deep seas.The performances of motion and mooring system dynamics are vital to designing a cost effective and durable floating platform.This paper describes a numerical model to simulate dynamic behavior of a new semi-submersible type floating offshore wind turbine(FOWT) system.The wind turbine was modeled as a wind block with a certain thrust coefficient,and the hydrodynamics and mooring system dynamics of the platform were calculated by SESAM software.The effect of change in environmental conditions on the dynamic response of the system under wave and wind loading was examined.The results indicate that the semi-submersible concept has excellent performance and SESAM could be an effective tool for floating wind turbine design and analysis.     

近海风电场风机桩群布局对海域水动力条件的影响

为了探讨海上风力发电场规划实施后风机桩群对附近海域水位、流速、潮通量等水动力条件的影响,建立了长江口、杭州湾及其附近海域大范围平面二维潮流数学模型,研究结果表明:风机实施的影响范围及程度与工程海域的潮流特性、风机布置形式等有关,就上海风电规划而言,风电场的实施基本没有对附近海域造成较大影响。     

Dynamic analysis of a dual-spar floating offshore wind farm with shared moorings in extreme environmental conditions

The concept of a shared mooring system was proposed to reduce mooring and anchoring costs. Shared moorings also add complexity to the floating offshore wind farm system and pose design challenges. To understand the system dynamics, this paper presents a dynamic analysis for a dual-spar floating offshore wind farm with a shared mooring system in extreme environmental conditions. First, a numerical model of the floating offshore wind farm was established in a commercial simulation tool. Then, time-domain simulations were performed for the parked wind farm under extreme wind and wave conditions. A sensitivity study was carried out to investigate the influence of loading directions and shared line mooring properties. To highlight the influence of the shared line, the results were compared to those of a single spar floating wind turbine, and larger platform motions and higher tension loads in single lines are observed for the wind farm with shared moorings. The loading direction affects the platform motions and mooring response of the floating offshore wind farm. Comparing the investigated loading directions to the 0-deg loading direction, the variation of mean mooring tension at the fairlead is up to 84% for single lines and 16% for the shared line. The influence of the shared line properties in the platform motions and the structural responses is limited. These findings improve understanding of the dynamic characteristics of floating offshore wind farms with a shared mooring system.     

An object-oriented method for fully coupled analysis of floating offshore wind turbines through mapping of aerodynamic coefficients

This work presents a novel object-oriented approach to model the fully-coupled dynamic response of floating offshore wind turbines (FOWTs). The key features offered by the method are the following: 1) its structure naturally allows for easy implementation of arbitrary platform geometries and platform/rotor configurations, 2) the analysis time is significantly faster than that of standard codes and results are accurate in situations where rotor dynamic contribution is negligible, and 3) an extremely flexible modeling environment is offered by the object-oriented nature of Modelica. Moreover, the current modeling facility used for the code development is open source and is naturally suitable for code sharing. In the present method, the aerodynamic model computes the aerodynamic loads through the mapping of steady-state aerodynamic coefficients. This modeling approach can be placed at the intersection between simplified aerodynamic methods, such as TDHMill, and full beam element/momentum-based aerodynamic methods. Aerodynamic loads obtained from the coefficients mapping are composed of a concentrated thrust and a concentrated torque. The thrust acts at the hub, while the torque is applied at the rotor low-speed shaft of a simplified rigid rotor equation of motion (EoM) used to emulate the rotor response. The aerodynamic coefficients are computed in FAST for a baseline 5 MW wind turbine. A standard rotor-collective blade-pitch control model is implemented. The system is assumed to be rigid. Linear hydrodynamics is employed to compute hydrodynamic loads. The industry-standard numerical-panel code Sesam-Wadam (DNV-GL) is used to preprocess the frequency-domain hydrodynamic problem. Validation of the code considers a standard spar-buoy platform, based on the Offshore Code Comparison Collaboration (OC3-Hywind). The dynamic response is tested in terms of free-decay response, Response Amplitude Operator (RAO), and the time histories and power spectral densities (PSDs) of several load cases including irregular waves and turbulent wind. The resulting model is benchmarked against well-known code-to-code comparisons and a good agreement is obtained.     

一种远海油气作业后勤保障的浮式码头概念设计

提出一种基于浮式码头的后勤保障设计,以保障远海油气作业。根据油气作业后勤保障的基本功能需求,对浮式码头的功能体系进行设计,并初步确定主尺度。根据功能模块化体积限制,对船舶进行概念设计,确定浮式码头的主要特性。分析浮式码头的稳定性和系泊要求,对浮式码头概念设计进行数值模型验证。结果表明,浮式码头概念设计可满足我国远海油气作业需求,有望形成一种新型远海油气作业后勤保障的新模式。     

基于“互联网+”的海洋钻井平台系统结构研究

互联网技术作为第三代工业革命的核心技术,为海洋钻井平台系统提供了新的发展方向。本文提出的基于“互联网+”的海洋钻井平台系统结构,结合了互联网技术的优势,优化了平台信息流和能量流;在原有电力控制网络的基础上,增加了“互联网+”远程故障诊断网络,以提高平台故障的排除速度;增加了“互联网+”海洋气象信息网络和海洋地质勘探网络,以提高平台的环境预测能力和地质勘探实时性;设计了基于互联网的能量管理系统可实现框架,将互联网和海洋钻井平台融合起来;还展望了基于“互联网+”海洋钻井平台的发展前景。     

海洋 平台技术的现状及发展趋势

  目的  冬季,海洋核动力平台在渤海区域作业时,因出现的浮冰会对其造成威胁,所以基于安全的考虑,需要对浮冰与平台的碰撞过程进行分析。  方法  首先,利用有限元数值仿真方法模拟渤海浮冰与海洋核动力平台的碰撞过程,并将数值模拟过程的阻力—位移曲线与冰锥受压实验数据进行对比,验证该数值模拟方法的可行性;然后,基于渤海冰情建立典型浮冰模型,通过浮冰与平台的撞击过程分析结构响应;最后,采取分别固定冰厚和固定冰速改变浮冰尺寸的方式,分析该平台对于浮冰的承载能力。  结果  结果显示,在碰撞过程中,骨材强度对该平台的承载能力影响较大,碰撞力会随着浮冰的持续挤压而不断增大,直至浮冰反弹;随着浮冰移动速度和冰厚的增加,该平台所能承受碰撞的浮冰尺寸也会相应降低。  结论  研究表明,平台与浮冰碰撞部位骨材的强度直接影响其自身的承载能力,分析发现浮冰移动速度比浮冰厚度对平台承载能力的影响更大。     

外岛式（东海大桥） 暴露试验站的设计及应用

基于海洋工程逐步向跨海化、外海化、岛屿化发展的现状以及已有研究成果的局限性,为获取外海条件下混凝土的破坏规律及影响因素,提出了建立外岛式现场暴露试验站,并阐述暴露试验站的选择原则及站址特点。研究成果对从设计、维护、管理等方面提高外海环境下混凝土结构的耐久性,以及保证离岸式大型基础设施结构的安全性和长期耐久性具有重要意义。