垂荡板对半潜式风机基础拖航过程中水动力性能及运动响应的影响分析

垂荡板对半潜式风机基础水动力性能有极大的影响，从而影响基础拖航安装过程的安全。为了研究垂荡板对半潜式基础拖航过程中运动响应的影响，建立了拖缆—WindFloat浮式风机半潜式基础拖航系统模型。首先，基于三维势流理论，采用AQWA开展了拖航系统的频域水动力分析，分析了垂荡板的尺寸及形状对基础水动力性能的影响规律；进一步采用时域方法对拖航系统的运动响应进行分析，探究了垂荡板的尺寸及形状在不同浪向下对基础运动响应的影响规律。结果表明：垂荡板能有效抑制基础的垂荡RAO，但垂荡板形状对基础的水动力性能无明显影响；具有圆形垂荡板的半潜式基础在拖航过程中的运动性能略优于六边形垂荡板，在原设计基础上继续增大垂荡板尺寸对基础运动响应的抑制效果呈现先增大后减小的趋势，说明半潜式风机基础存在一个最优的垂荡板尺寸。

Investigation on the effects of heave plate on the hydrodynamics and dynamic responses of semi-submersible foundation of offshore wind turbine during the towing operation

The heave plate has a significant influence on the hydrodynamic performance of the floating wind turbine semi-submersible foundation, and thus may influence the safety of the wet towing and installation operations of the semi-submersible foundation. To investigate the effects of heave plate on the dynamics of the semi-submersible foundation during its wet towing operation, a numerical dynamic model is established for the towline-WindFloat semi-submersible foundation. Firstly, based on the three-dimensional potential flow theory, the frequency domain hydrodynamic analysis of the towing system is carried out by using AQWA, and the effects of the size and shape of heave plate on the hydrodynamic response of WindFloat foundation are analyzed. Then, the time domain method is further used to analyze the dynamics of the towing system, and the effects of the size and shape of heave plate on the dynamics of the foundation under different wave directions are investigated. The results show that the heave plate can effectively reduce the heave RAO of the foundation, but the shape of the heave plate has no significant effect on the hydrodynamic performance of the foundation. In addition, the motion performance of the semi-submersible with circular heave plate during towing is found to be slightly better than that of the foundation with hexagonal heave plate. Based on the original foundation design, with the increase of the heave plate size, the motion inhibition effect shows a tendency to increase first and decrease later, which indicates that there exists an optimal heave plate size for a specific semi-submersible foundation.