海上风电场工程海流设计流剖面计算模型研究

Research on the Calculation Model of Design Current Profile for Offshore Wind Farm

为满足海上风电场工程设计与建设需要,研究合理可靠且简单易行的海流设计流剖面计算方法十分必要。基于海流成因及组成项分析,本文提出采用潮流、风海流与设计波生流的矢量求和,并考虑综合安全系数的海流设计流剖面计算模型。风海流由季节性的盛行风持续吹拂海面形成,波生流则由大风引发大浪生成。波生流分层流速计算采用基于Stokes二阶波的非周期性项Russel-Osorio修正式,适用于海上风电场所在的深水区及绝大部分过渡区,由其参与组成的海流不会对波流共同作用下的波浪荷载重复计量。根据工程海域水文气象条件经分层计算组成设计流剖面,可避免简单流剖面模型的经验性与任意性。研究结果有利于合理确定海上风电场及类似工程的海流载荷与基础冲刷的水动力条件。

It is necessary to study a reasonable,reliable,and simple method for calculating ocean current design flow profile to meet the needs of offshore wind farm engineering design and construction.Based on the analysis of the causes and components of the current,a calculation model of the design current profile is proposed,which uses the vector summation of tidal current,wind current and design wave generated current,and considers the comprehensive safety factor.The wind driven current is formed by the seasonal prevailing winds continuously blowing the sea surface,while the wave generated current is generated by the strong wind causing waves.The calculation of layered velocity of wave induced currents adopts the Russel-Osorio correction formula based on the non-periodic term of Stokes 2nd-order waves,which is applicable to the deep water waves and most of the transition zones where offshore wind farms are located.The ocean currents composed of it will not produce repeated measurements of wave loads under the combined action of waves and currents.According to the hydrological and meteorological conditions of the engineering sea area,a design flow profile is formed through layered calculation,which can avoid the empiricism and arbitrariness of a simple flow profile model.The method presented in this article is beneficial for determining the ocean current load and foundation erosion hydrodynamic conditions of offshore wind farms and similar projects in a reasonable manner.