风载荷对不同海上浮式风力机平台运动特性影响对比研究

COMPARATIVE STUDY ON EFFECTS OF WIND LOAD ON MOTION CHARACTERISTICS OF DIFFERENT OFFSHORE FLOATING WIND TURBINE PLATFORMS

为探究风载荷对不同漂浮式风力机平台影响,分别建立基于单桩式、半潜式及驳船式3种平台的漂浮式风力机整机模型,结合叶素-动量理论、辐射/绕射理论及有限元方法,研究不同工况下3种典型漂浮式风力机平台的时频运动响应特性。结果表明:仅波浪载荷作用时运动响应标准差均小于风波耦合作用时,风载荷使平台偏离平衡位置明显,且对各平台纵荡响应较其余响应更敏感;对于纵荡响应,风载荷使3个平台固有频率处响应峰值均有所增大;对于垂荡响应,风载荷使单桩式平台固有频率处响应峰值有所减小、半潜式平台垂荡-纵摇耦合处及固有频率处响应峰值有所增大,但对驳船式平台垂荡响应可忽略不计;对于纵摇响应,风载荷使单桩式平台固有频率处响应峰值有所增大,并使半潜式平台发生纵荡-纵摇耦合运动,但对驳船式平台纵摇响应影响甚微;风载荷是平台发生耦合运动的关键因素;波浪载荷是影响驳船式平台垂荡及纵摇响应的关键因素。

In order to study the effects of wind load on different offshore wind turbine platforms,this paper modeled offshore wind turbines based on OC3-Hywind Spar,UMarine Semi-submersible and ITI Energy Barge platforms respectively.The time-frequency motion response characteristics of three typical floating wind turbine platforms under different working conditions are studied combined with the BEM theory,the radiation/diffraction theory and finite element method.The results show that the standard deviation of motion responses under wind load is lower than that of wind wave coupling.The wind load makes the platforms deviate from the equilibrium position significantly.And the surge response of each platform is more sensitive than other responses.For the surge response,the wind load increases the response peaks at the natural frequency of three platforms.For the heave response,the wind load decreases the response peak at the natural frequency of the Spar platform and increases the response peak of the coupling motion of heave and pitch and the natural frequency of the Semi-submersible platform.However,the wind load has little effect on the pitch response of the Barge platform.For the pitch response,the wind load increases the response peak at the natural frequency of the Spar platform and causes the coupling motion of surge and pitch of Semi-submersible platform.However,the wind load has little effect on the pitch response of the Barge platform.The wind load is the key factor for the coupling motion of the platforms.The wave load is the key factor affecting heave and pitch response of Barge platform.