共查询到20条相似文献,搜索用时 156 毫秒
1.
假设漂浮式风力发电站Hywind用于我国海域内,对其在涌浪、浮力及内部减振器共同作用下的扭转响应进行了理论分析。针对电站塔柱的具体结构和涌浪形式,按调频减振的原理设计了三款减振器。经过模型简化后,使用分离求解双向耦合的数值模拟方法对减振器抑制Hywind电站塔柱在涌浪作用下发生的周期性受迫扭转振动的特性进行求解。数值结果用于指导减振器的参数优化,优化后的三种减振器的抑振力幅值接近了理论设计值,其中联合减振器结合了其余两者的优势,在相同的空间中安装1.82%的减振质量可以抑制17%的扭振幅度,具有进一步研究和推广价值。 相似文献
2.
针对在西非海域作业的某多点系泊30万吨FPSO,研究西非海域特定环境条件下的双向风浪及涌浪的联合作用对该FPSO运动及载荷响应的影响。文中基于三维势流理论对FPSO运动响应进行数值分析,并与试验值幅值响应算子(RAO)对比。利用双Ochi-Hubble谱的短期预报,论述FPSO在双方向风浪及涌浪作用下的运动幅值、加速度及载荷响应;论述涌浪方向对运动及载荷响应的影响,并考虑涌浪周期敏感性的影响,对FPSO运动加速度、幅值、波浪弯矩、波浪剪力进行数值分析;总结了FPSO在双方向风浪及涌浪作用下运动及载荷响应根据浪向的变化特点,以及FPSO波浪载荷受风浪和涌浪周期敏感性影响的特点,为西非FPSO后续的结构设计提供参考。 相似文献
3.
4.
5.
6.
7.
海上的波浪观测资料统计表明,海上纯风浪和纯涌浪的出现机会比较少,大部分以混合浪形式出现,其频谱结构多为双峰甚至多峰。研究双峰谱波浪的模型表述和数值模拟技术,对三种典型的双峰谱海浪进行了数值模拟,仿真结果表明了双峰谱海浪数值模拟的有效性。 相似文献
8.
9.
10.
11.
12.
The Chesapeake Bay is vulnerable to severe flooding caused by hurricanes and strong Northeasters. A 3D storm surge model of the Chesapeake Bay is developed for studying the impact of model domain size, wind directions and Ekman transport on the storm surge in the Chesapeake Bay. The model encompasses the Chesapeake Bay and the US East Coast shelf to reduce the influence of model domain size on surge prediction inside the Chesapeake Bay and to account for both local and remote wind effects. This study used 3D model experiments, with respect to different wind directions, to diagnose the relative influences of the local and remote wind effects and Ekman transport on spatial surge distribution during storm events. The model results confirmed that spatial surge distribution can be well explained by the superposition of two distinct physically driven mechanisms during a storm event: incoming surge wave caused by remote effects and local wind forcings. A large model domain is a necessity for predicting storm surge accurately inside the Chesapeake Bay. The model results suggest that the interactions of the incoming surge propagating into the Bay and the local wind forcing from N and NE directions result in an enhanced setup in the lower to middle portions of the Bay, whereas the superposition of incoming surge and the local wind forcing from S and SE directions enhance the surge in the upper Bay region. A combined northwesterly wind over the middle to upper portions of the Bay and southwesterly wind over the lower Bay can cause a large setdown throughout the entire Bay. The Ekman setup along the coast contributes significantly to the water level variations during storm events. It enhances (reduces) surge inside the Bay under the wind forcings from N and NE (SW, S, and SE) directions. 相似文献
13.
波浪平均漂移力是影响FPSO系统系泊、立管安装和卸载的重要外在荷载。文中针对英国北海正投入使用的萨哈林型式FPSO,应用高阶边界单元方法对其二阶水动力特性进行了计算分析,计算中考虑了物体的几何对称性,FPSO系统所受到的纵荡,横荡以及首摇方向的波浪平均漂移力采用近场解法在湿表面上直接进行压力积分获得。与常数单元方法相比,该方法具有很高的精度,特别是对于高频波浪能得到可靠的收敛解。研究表明为了使得FPSO系统在恶劣海况下安全使用,FPSO系统必须始终保持迎浪状态工作。 相似文献
14.
15.
16.
在大型重力式分层流水槽中,采用重力塌陷造波和模型半柔性约束方法,结合位移和倾角测量技术,对下凹型内孤立波作用下的细长潜体模型运动特性进行了实验研究,获得了模型垂/纵荡、横/纵摇和质心轨迹运动规律。研究表明:细长潜体模型在下凹型内孤立波作用下的质心运动轨迹近似于椭圆;模型垂/纵荡和横/纵摇运动主要受到波幅因子α(内波波幅与模型长度之比)和潜深的影响;当α固定时位于内孤立波上/下方的模型主要表现为纵荡,而位于穿越内孤立波位置的模型主要表现为垂荡,实验进一步证实了模型运动特性与内孤立波内部流场分布的相关性。 相似文献
17.
采用曲线坐标系下的准三维近岸流波流耦合数值模型,采用边界适应曲线计算网格和两层嵌套方法,设计一套简单实用的天文潮预报系统,并引入风场以及考虑天文潮和风暴潮之间非线性作用的开边界水位,对2003年渤海发生的一次温带风暴潮进行模拟,计算结果与实测潮位吻合较好。 相似文献
18.
Numerical study of ice-induced loads on ship hulls 总被引:1,自引:0,他引:1
A numerical model is introduced in this paper to investigate both global and local ice loads on ship hulls. This model is partly based on empirical data, by which the observed phenomena of continuous icebreaking can be well reproduced. In the simulation of a full-scale icebreaking trial, the interdependence between the ice load and the ship’s motion is considered, and the three degree-of-freedom rigid body equations of surge, sway and yaw are solved by numerical integration. The variations in the level ice thickness and in the strength properties of ice can also be taken into account. The simulated ice loads on ship hulls are discussed through two case studies, in which the ship’s performance, the statistics of ice-induced frame loads, and the spatial distribution of ice loads around the hull are analyzed and compared with field measurements. As far as we know the present paper is the first to integrate all the features above. It is hoped that further studies on this numerical model can supplement the field and laboratory measurements in establishing a design basis for the ice-going ships especially for ships navigating in the first-year ice. 相似文献
19.
Chyan-Deng Jan Chih-Ming Tseng Ji-Shang Wang Yun-Hsiang Cheng 《Journal of Marine Science and Technology》2006,11(3):193-200
The relation between typhoon surges and typhoon characteristics measured at Kenfang Tidal Station on the northeast coast of
Taiwan was studied in this paper. Typhoon characteristics include the typhoon center atmospheric pressure, the typhoon near-center
wind speed, the typhoon storm radius, the distance between the typhoon center and the tidal station, and the typhoon approach
tracks. The results show that the typhoon surge deviation is strongly dependent on typhoon characteristics. An empirical typhoon
surge formula is proposed in terms of the typhoon wind speed, the typhoon storm radius, and the distance between the typhoon
center and the tidal station. The coefficients in the empirical formula were evaluated, based on the measured typhoon surge
data at Kenfang Tidal Station. The storm surge deviations at Kenfang Station during Typhoons Doug (1994) and Herb (1996) estimated
using the proposed empirical formula were compared with the measured data as well as with the results of a numerical study. 相似文献
20.
为了更科学地评判山体滑坡灾害导致的海事风险并且科学实施水上交通管制决策,研究山体滑坡海事风险的三维测度方法。以大中规模剧动式滑坡涌浪为研究对象,根据山体滑坡海事风险的形成过程研究其海事风险的三维测度方法,提出了以山体滑坡变形破坏阶段、滑坡涌浪规模、涌浪损毁船舶的系统风险综合系数为测度指标的海事风险评判模型,并通过实例说明该方法及风险评判模型的应用。研究结论表明:该海事风险测度方法及评判模型,考虑了山体滑坡险情水上交通管制的主要因素,全面地反映了山体滑坡灾害导致的海事风险特征。 相似文献