浮式风渔平台水动力和气动力响应特性

Hydrodynamic and aerodynamic response characteristics of floating wind-aquaculture platforms

浮式风机-养殖多功能平台(风渔平台)能够更加充分且高效地开发和利用深远海资源,但由于这种平台同时集成了浮式风机和大型网箱的装备模块,其力学特性将更为复杂。本文综合考虑了风、浪、流联合作用下风轮脉动风载荷及变速变桨控制、浮体波浪载荷和网衣系统黏性载荷,基于整体系统的水动-气动-控制一体化分析方法,研究了风渔平台的动力学响应特性,重点关注了不同海况下平台运动响应、锚链张力、浮筒连接钢结构截面载荷以及风机叶片气弹性响应,并评估了网衣对相关运动响应的影响规律。结果表明:风渔平台纵荡和纵摇主要包含低频慢漂和波频运动两个成分,随着海况愈发恶劣,波频成分响应逐渐增大;锚链张力与平台运动相关,其载荷主导频率与纵摇和纵荡运动规律较为一致;网衣对平台运动以及锚链载荷的影响主要集中在低频区间,多数情况下具有抑制效应;不同浮筒之间的截面载荷均以轴向力贡献为主,且波频成分占据主导地位,但迎浪侧两个浮筒受锚链载荷影响,其低频成分同样十分显著;风机工作时叶片弹性响应由风速与转速主导,而停机时该响应主要由纵摇和纵荡运动引起。研究成果为浮式风渔平台的结构安全设计提供了参考。

The floating wind-aquaculture multi-functional platforms act as a more comprehensive and efficient way of using deep-sea resources.However,this multifunctional offshore equipment presents more complex dynamic characteristics due to the integration of the dynamic features of both floating wind turbines and fish farming cages.Taking into account of the fluctuating wind load on the wind turbine,the variable speed and pitch control,the wave load on the floating body,and the viscous load on the fish-net system under the combined effect of wind,wave and current,the dynamic response characteristics of the wind-aquaculture platform are studied by using the method of hydro-aero-servo integration on the entire system.Specifically,attention was given to the motion response of the platform,the mooring line tension cross-section load of steel structure between pontoons and the aero-elastic response of the blades under different sea conditions.Additionally,the effects of the fish net on relevant motion responses are evaluated in this study.The results show that:the surge and pitch of wind-aquaculture platform mainly consist of low frequency slow-drift and wave frequency motion.As the sea state deteriorates,the response of wave frequency component gradually intensifies.The mooring line tension is related to the platform motion,and the load dominant frequency aligns with the surge and pitch motion.The nets primarily affect platform motion and mooring line load in the range of low frequency,exerting a suppressive effect in most cases.The axial force of steel structure exhibits a primary contribution to the cross-sectional load between different pontoons compared to the bending moments,and it is dominated by wave-frequency component.However,under the influence of mooring lines load,the axial force between pontoons on the wave side also experiences a significant low-frequency component.The blade's elastic response is dominated by the wind speed and rotational speed during operation,while the surge and pitch motion play a major role in its response when the turbine is shutdown.The numerical results provide reference for ensuring structural safety in the design of floating wind-aquaculture platforms.